F AA-AM-73-7 

THE RELATIONSHIPS OF AGE AND ATC EXPERIENCE 

TO JOB PERFORMANCE RATINGS OF TERMINAL 

AREA TRAFFIC CONTROLLERS 

Bart B. Cobb, M.S. 

Peter L. Nelson, B.A. 

John J. Mathews, B.A. 

FAA Civil Aeromedical Institute 

P.O. Box 25082 

Oklahoma City, Oklahoma 73125 

April 1973 

Availability is unlimitffl.. Document may be released 

to the National Technical Information Service, 

Springfield, Virginia 22151, for sale to the public. 

Prepared for 

DEPARTMENT OF TRANSPORTATION 

FEDERAL AVIATION ADMINISTRATION 

Office of Aviation Medicine 

Washington, D.C. 20591 
The contents of this report reflect the views of the Civil Aeromedical 

Institute which is responsible for the facts and the accuracy of the data 

presented herein. The contents do not necessarily reflect the official views or 

policy of the Department of Transportation. This report does not constitute 

a standard, specification or regulation. 
------·---------··------------------------ -------------------------------------- ---------------- ------------------------------------------------ ------------------------------- ---------------------· ----, 

stration, Office of Aviation 

al Institute, Oklahoma City, 

TIONSHIPS OF AGE AND 

O JOB PERFORMANCE 

AL AREA TRAFFIC CON

Cobb, Peter L. Nelson, and 

 1973, 48 pp. Report No. 

collection of experimental ratings of 

er data for several hundred journey

alists of 17 high-IFR-traffic-density 

ontrol facilities. Significant inverse 

 between the job ratings and both 

nure in FAA ATC work. Results of 

f data for dichotomized groups aged 

1 and older" within each of several 

pings indicated that ( 1) the younger 

ence level tended to receive higher 

ver 40 years old, and (2) the greater 

formance ratings pertained to the 

I. Col,)b, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J. 

DesC1··iptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings 

Federal Aviation Administration, Office of Aviation 

Medicine, Civil Aeromedi cal Institute, Oklahoma City, 

Oklahoma. THE RELATIONSHIPS OF AGE AND 

ATC EXPERIENCE TO JOB PERFORMANCE 

RATINGS OF TERMINAL AREA TRAFFIC CONTROLLERS by Bart B. Cobb, Peter L. Nelson, and 

John J. Mathews, April 1973, 48 pp. Report No. 

F AA-AM-73-7. 

This study involved the collection of experimental ratings of 

job performant e and other data for se,·eral hundred journeymen radar control specialists of 17 high-IFR-traffic-density 

'l'erminal Area Traflic Control facilities. Significant inverse 

relationships were found between the job ratings and both 

chronological age and tenure in FAA AT(' work. Results of 

a comparative analysis of data for dichotomized groups aged 

"40 and younger" and "41 and older" within each of several 

length-of-experience groupings indicated that ( 1) the younger 

subjects of every experience level tended to receive higher 

evaluations than those over 40 years old, and (2) the greater 

mean differences in performance ratings pertained to the 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J. 

Desc1·ipt01-s 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

.Job Ratings 

Peer Ratings 

---------------------------------------·-- ------------------------------- ---------'- ----------------------------------------------------------------------------------- -------------------------------: 

 having over 10 years experience. 

analysis indicated that, when the 

oretically nullified, or held constant, 

ly negligibly with performance. A 

d that if the subjects had possessed 

erience, their ratings would still have 

d significantly so, with their ages. 

sted that ATCS proficiency is more 

of factors associated with aging than 

umed effects stemming from lengthy 

dichotomized age groups having over 10 years experience. 

However, a regression analysis indicated that, when the 

variance of age was theoretically nullified, or held constant, 

experience correlated only negligibly with performance. A 

similar analysis indicated that if the subjects had possessed 

identical amounts of experience, their ratings would still have 

correlated negatively, and significantly so, with their ages. 

Other results also suggested that ATCS proficien<"y is more 

apt to decline as a result of factors associated with aging than as a consequence of presumed effects stemming from lengthy 

ATC experience. 
stration, Office of Aviation 

al Institute, Oklahoma City, 

TIONSHIPS OF AGE AND 

O JOB PERFOR:\IANCE 

AL AREA TRAFFIC CON

Cobb, Peter L. Kelson, and 

1973, 48 pp. Report No. 

collection of experimental ratings of 

er data for sen•ral hundred journey

alists of 17 high-IFU-traffic-density 

ontrol facilities. Signifh:ant inverse 

 between the job ratings am! both 

nure in FAA A'J'C work. Uesults of 

f data for dichotomized groups aged 

1 and older" within each of several 

pings indicated that ( 1) the younger 

ence level tended to reteive highe1· 

er 40 years old, and (2) the greater 

formance ratings pertained to the 

 having over 10 years exverience. 

analysis indicated that, when the 

oretically nullified, or hel<l constant, 

ly negligibly with performance. A 

d that if the subjects had po><sessed 

rience, their ratings would still ha\·e 

m! significantly so, with their ages. 

sted that ATCS proticierwy is more 

of factors assoriated with aging than 

umed effects from lengthy 

I. Cobb, B. B. 

II. :\elson, I'. L. 

III. l\lathews, 

J. J. 

Desc1·iptors 

Aging Effects 

Work Experience 

Effects 

Air· Traffic 

< 'on trollers 

.Toll Itatings 

l'ecr Hating:; 

Federal Aviation Administration, Office of Aviation 

Medicine, Civll Aeromedical Institute, Oklahoma City, 

Oklahoma. THE RELATIONSHIPS OF AGE AND 

ATC EXPERIENCE TO JOB PERFO.RMANCE 

RATINGS OF TERMINAL AREA TRAFFIC CONTROLLERS by Bart B. Cobh, Peter L. Nelson, and 

John J. Mathews, April 1973, 48 pp. Report No. 

FAA-AM-73-7. 

This study involved the collection of experimental ratings of 

job performance and other data for several hundred journeymen radar control specialists of 17 high-IFll-tratfic-density 

Terminal Area Trame Control facilities. Signifkant inverse 

relationships were found between the job · ratings and both 

chronological age and tenure in FAA ATC work. Results of 

a comparative analysis of data for dichotomized groups aged 

"40 and younger" and "41 and older" within each of several 

length-of-experience groupings indicated that (1) the younger 

subjects of every experience le\·e! tended to receive higher 

evaluations than those over 40 years old, and (2) the greater 

mean differences in performance ratings pertained to the 

dichotomized age groups having over 10 years experience. 

l!owe\·er, a regression analysis indicated that, when the 

varian<.:e of age was theoretitally nullified, or held constant, 

experience correlated only negligibly with performance. A 

f<imilar analysis indicated that if the subjects had possessed 

identical amounts of experience, their ratings would still have 

correlated negatively, and significantly so, with their ages. 

Other results also suggested that ATCS proficien<"y is more 

apt to decline as a result of factors associated with aging than as a consequence of presumed effects stt>mrning from lengthy 

A 'l'(' Pxperience. 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J . J . 

Descriptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings 
TECHNICAL REPORT STANDARD TITLE PAGE 

1. Report No. ? . Government Accession No. 3. Recipient's Catalog No. 

FAA-AM-73-7 

4. Title and Subtitle 5. Report Date 

THE RElATIONSHIPS OF AGE AND ATC EXPERIENCE TO JOB April 1973 

PERFORMANCE RATINGS OF TERMINAL AREA TRAFFIC 6 . Performing Organ i zation Code 

CONTROLLERS 

7. Author( s) 8 . Performing Organi zotion Report No. 

Bart B. Cobb, M.S., Peter L. Nelson, B.A., and 

John J. Mathews, B.A. 

9. Performing Organization Nome and Address 10. Work Unit No. 

FAA Civil Aeromedical Institute 

P. o. Box 25082 11. Contract or Grant No. 

Oklahoma City, Oklahoma 73125 

13. Type of Report and Period Covered 

12. Sponsoring Agency Name and Addres• 

Office of Aviation Medicine ClA.M Report 

Federal Aviation Administration 

800 Independence Avenue, s .w. 14 . Sponsoring Agency Code 

Washington, D. c. 20591 

15. Supplementary Notes 

This research was conducted under Tasks AM-D-68-PSY-2, AM-B-69-PSY-2, 

AM-A-70-PSY-2, AM-B-71-PSY-2, AM- B-72- PSY- 2, and AM-B-73-PSY-2. 

16. Abstract 

This study involved the collection of experimental ratings of job performance and 

other data for several hundred journeymen radar control specialists of 17 highIFR-traffic-density Terminal Area Traffic Control facilities. Significant inverse 

relationships were found be tween the job ratings and both chronological age and 

tenure in FAA ATC work. Results of a comparative analysis of data for dichotomized 

groups aged "40 and younger" and "41 and older" within each of several length-ofexperience groupings indicated that (1) the younger subjects of every experience 

level tended to receive higher evaluations than those over 40 years old, and 

(2) the greater mean differences in performance ratings pertained to the 

dichotomized age groups having over 10 years experience. However, a regression 

analysis indicated that, when the variance of age was theoretically nullified, or 

held constant, experience correlated only negligibly with performance. A similar 

analysis indicated that if the subjects had possessed identical amounts of experience, their ratings would still have correlated negatively, and significantly so, 

with their ages. Other results also suggested that ATCS proficiency is more apt 

to decline as a result of factors associated with aging than as a consequence of 

presumed effects stennning from lengthy ATC experience. 

17. K"y Words 18. Distribution Statement 

Aging Effects Availability is unlimited. Document may 

Work Experience Effects be released to the Nat iona 1 Technical 

Air Traffic Controllers Information Service, Springfield, Virginia 

Job Ratings 22151, for sale to the public. 

Peer Ratings 

19. Security Clossif. (of this report) 20, Security Clossif. (of this page) 21. No. of Pages 22. Price 

Unclassified Unclassified 48 $3.00 

Form DOT F 1700.7 !B·69l 

I. Introduction 

II. Methodology 

TABLE OF CONTENTS 

Page 

1 

2 

Selection of TATC Facilities ------------------------------ 2 

Peformance Evaluation Form Used ------------------------ 3 

Performance Ratings by Supervisors, Crew Chiefs, and Peers __ 4 

Rating the Relative Importance of Performance-Rating-Form 

Items ----------------------------------------------------- 4 

Collection of Job Ratings and Other Data ------------------ 4 

III. Results and Discussion --------------------------------------- 5 

The Total Sample ----------------------------------------- 5 

Reliability of RLGR Ratings ---------------------------- 7 

Empirical Interrelationships of Age, Experience, and RLGR 

Ratings ------------------------------------------------- 7 

Means of RLGR Ratings by ATCS Age Group ____________ 9 

Means of RLGR Ratings by FAA ATC Experience GroupIngs ---------------------------------------------------- 11 

Interaction Effects of Age and Experience ________________ 13 

A. Performance of Dichotomized Age Groups by Experience Level ----------------------------------------- 13 

B. Performance of Dichotomized Experience Groups by 

Age Level ----------------------------------------- 13 

C. Dominance of Aging OYer Experience Effects ________ 16 

Performance Evaluations ·weighted in Terms of Item Import 

Ratings ------------------------------------------------- 16 

Facility Differences ---------------------------------------- 16 

Correlative Data for Combined Facilities ________________ 17 

Comparison of Empirical Relationships by Facility ________ 17 

Comparison of Results for High-, Intermediate-, and LowRanked Facilities ______________________ ··- ___ _ __ _ ___ ____ _ 19 

Quest for Explanations Why Few Older ATCSs Worked 

Within Highest-Ranked Facilities ------------------------ 23 

A. Training-Entry Age ------------------------------- 23 

B. Facility Transfers ---------------------------------- 23 

C. Mean Ratings by Age LeYel for A TCSs of the Three 

Subsamples ---------------------------------------- 24 

Findings for Combined Intermediate and Low Subsamples 

Only --------------------------------------------------- 25 

IV. Summary and Conclusions ------------------------------------ 26 

ACKNOWLEDGMENTS 

The authors gratefully acknowledge the assistance rendered by :\fessrs. 

Frederick H. Ottersberg, Francis .T. Bassett, Harry L. Burton, Edward 

T. Harris, Norman S. Kingham, Gordon McDonald, Michael .T. Ollis, and 

others of the office of the Air Traffic Service in the planning and datacollection phases of this study, and the assistance in statistical matters 

provided by Dr. Earl D. Folk, Chief of CAMI's Biostatical Staff. 

THE RELATIONSHIPS OF AGE AND ATC EXPERIENCE 

TO JOB PERFORMANCE RATINGS OF TERMINAL 

AREA TRAFFIC CONTROLLERS 

I. Introduction. 

Numerous studies2- 4 10- 14 by the Ci vi! Aeromedical Institute (CAMI) during the past 13 years 

have been remarkably consistent in indicating 

chronological age at time of entry into Air Traffic 

Control Specialist ( ATCS) training to be inversely related to measures of performance in the 

FAA Academy's basic ATC training courses and 

post-Academy attrition-retention status. Such 

studies2 4 10 12 14 have revealed that personnel under 31 years of age who possessed little or no 

pre-FAA ATC-related experience, as well as 

former military controllers no older than 35, were 

much more apt to succeed in ATCS trainincr 

than their older colleagues. Moreo,·er, r: 

search2 12- 14 has repeatedly demonstrated that 

t~ainees over 35 years old also tend to score sigmficantly lower than those of younger age on a 

wide variety· of aptitude tests having validity 

for prediction of training performance. 

A matter of more crucial imi)Ortance however ' ' 

concerns the extent to which job perforrr.ance at 

the journeyman ATCS level may be associated 

with age. Findings relevant to this issue were 

first reported in 1962 by Trites and Cobb12 for a 

study in which age at entry into trainincr was 

validated against Academy training perfor~ance, and also against experimentally deriYed ratings 

of job performance rendered one to five years 

after Academy graduation. The authors concluded that the chances of an individual beincr 

considered a satisfactory contyoller are approxt 

mately one in five if he is 33 years of age or older 

upon entering training, whereas the chances are 

about one in two if he is younger than 33. 12 In 

1964, a similar study14 of seYeral hundred additional ATCS personnel yielded results indicatincr ,.., 

that Academy graduates with training entry ages 

of 33 and over were much more likely, relati,-e 

to younger personnel, to have their supervisors 

1 

evaluate their job performance as "marcrinal ., b ' 

rather than "satisfactory." The majority of subjects involved in both these earlier investicrations b ' howeYer, had not advanced to journeyman-controller status by the time the experimental ratings were collected; no distinction was made in 

either study with respect to the subjects' General 

Schedule ( GS) levels (i.e., pay grades), and the 

major findings were based on analyses in which 

the data for Air Route Traffic Control Center 

(ARTCC) personnel were combined with those 

collected for A TCSs at Terminal Area Traffic 

Control (TATC) facilities. 

The findings obtained in the research mentioned above sen-ed to further augment the apprehensiveness of many FAA officials regarding 

the potential effects of aging upon the performance of journeymen-leYel ATCSs, particularly 

at high-traffic-volume facilities. Moreover, the 

rapidity with which aviation was expanding 

underlay the consensus that ATC work was becoming increasingly more "stressful" and thence 

provided a reasonable basis for suspecting that 

cumulative stress effects arising from lengthy 

service in active control work might be at least 

partially responsible for age-related differences 

in performance. 

The need for a more definiti,-e assessment of 

the interrelationships of age, experience, and 

ATCS performance led to a survey-type study1 

in 1965 in which experimental ratings of job 

performance, tenure information, and other data 

were collected for over 500 journeymen radar 

c~ ntrollers at four ARTCC facilities. The study 

yrelded a number of important findings. A 

statistically significant im·erse relationship was 

obtained bet\veen age and rating le,·el. Mean 

group ratings for controllers oYer 40 years of age 

were significantly lower than those of younger 

groups. Length of FAA ATC experience, when 
considered independently of age, proved to be 

negligibly related to rating le,·el. While no significant interaction effects of age and experience 

were discoyered, consistent trends in the results 

were found indicating progressively higher mean 

ratings extending from the lesser to the more 

experienced groups of controllers who " ·ere less 

than 41 years of age. For ATCSs of age 41 

and older, howm·er, the mean ratings of the 

more experienced groups were lower, though not 

significantly lower, than those of the less experienced groups. 'Vithin e,·ery experience leYel, 

the ATCSs of age 40 and younger had higher 

mean ratings than the older controllers and the 

mean differences between the ratings of the dichotomized age groups were progressiYely larger 

from the moderate to the lengthy experience 

levels. Copies of the "Employee Appraisal 

Record" (EAR, FAA Form 3693) were made 

available for 300 of the 568 ATCSs involved in 

the study. Ratings based on Part IV of the 

instrument proved much less effective than the 

experimental r1rtings for purposes of individual 

differentiation. Although findings stemming 

from analyses in which the operationally derived 

ratings served as criteria were therefore not as 

definitive as those based on the experimental 

ratings, they were in general agreement with the 

latter. 

The present report concerns qn investigation 

wherein procedures, somewhat similar to those 

used in the 1965 study of journeymen ARTCC 

(or Center) controllers, were employed to determine the interrelationships of age, FAA ATC 

experience, and ratings of job performance for 

journeymen ATCSs engaged in Terminal Area 

Traffic Control at several high-traffic-density 

airports. The ratings of job performance, background information, and other data were collected in conjunction with a comprehensive study 

which also included an assessment of the controllers' attitudes and motivations regarding 

their work and job environment. Other research 

priorities,2- 4 which arose shortly after comr.letion 

of the data collection phase (in February 1969), 

precluded rapid progress in the processing and 

analysis of the diverse types of information obtained for the 614 subjects. The first8 of two 

anticipated reports on the study was published 

in July 1971. It focused upon describing the 

nature, incidence, and intensity of the controllers' work attitudes and the relationship of the 

2 

latter to age, experience, and performance. However, most analyses concerning the potential 

effects of age and experience upon level of job 

performance were reserved for inclusion in the 

present report. 

II. Methodology. 

Various groups within the FAA participated 

in formulation of the overall research design and 

in the development and tryout of the performance evaluation scales and other data collection 

devices. The impetus for much of this support 

originated with the FAA Headquarters' Office 

of Air Traffic Service ( ATS), through which 

all aspects of the study were coordinated. However, the helpfulness of ATS officials extended 

far beyond providing coordinative support. They 

assisted in the planning of certain phases of the 

project, reviewed and helped revise preliminary 

forms of the questionnaires and rating devices, 

and selected the specific TATC facilities at which 

the controller personnel were evaluated. More 

importantly, five ATCSs on the staff of Headquarters' ATS were designated to visit 14 facilities (of the 17 ultimately selected) for 

purposes of briefing the participants and collecting data. The sixth member of the data 

collection team, an ATCS from the National 

Aviation Facilities Experimental Center (NAFEC) who had earlier headed a team of NAFEC 

ATCSs in developing the initial version of the 

performance evaluation form, visited two facilities. The remaining member of the survey team, 

a CAM! researcher with no experience in ATC 

work, collected data at one facility only. 

Selection of T ATO Facilities. The selection 

of the facilities at which data were collected was 

based on a number of considerations. First, it 

was reasoned that if age and experience were 

indeed inYersely related to performance, the relationships would probably be more pronounced 

at high IFR-density airports than at those having either relatively low IFR operations or VFR 

traffic only. ATC officials and the principal investigators therefore concurred that the selection 

of the facilities should be made from among 

those which, at that time, were of Level-III 

status (i.e., facilities having 100,000 or more IFR 

operations annually) . 

Inasmuch as the controllers at three of the 

four airports having the heaviest IFR traffic 
loads had just recently participated in other 

FAA studies, ATS indicated that those three 

should be excluded from the proposed snn-ey to 

preclude further disruption of those controllers' 

work schedules. Due to n1rious reasons, it was 

also decided that each fa cility at " ·hich the IFR 

room was not located within or near the tower 

should be excluded from the study. Bi,·ariate 

frequency distributions of age and experience 

of the controllers at each of the remaining Le,·elIII T ATC facilities were next prepared and 

examined. (The distributions were obtained 

through analysis of ADP tape records, current as 

of .T anuary 1968, which FAA Headquarters provided.) Twenty facilities for which the ranges 

of age and experience appeared to offer the best 

potential for study of possible interaction effects 

were tentatively selected. Due to limited traYel 

funds, however, no visits were made to three of 

the 20. 

During the fiscal year 1969 (a period approximately midway in which the ATCS ratings were 

collected), the 17 selected facilities had a combined total of 3,77 4,576 IFR operations; the 

range was from 111,731 at Indianapolis, Indiana, 

to 374,354 at the Atlanta, Georgia, Municipal 

Airport, and the overall average per facility was 

222,033. 

Perf01'mance Evaluation F01vm Used. The 

CAMI study of ARTCC personnel had shown, 

as mentioned earlier, that supervisory ratings of 

ATCS performance based on the EAR (FAA 

Form 3693) offered little potential for individual 

differentiation. The distribution of such ratings 

was abnormal; less than one-half of one per cent 

of the ratings were in the lowest two of five 

categories whereas the ratings received by the 

majority of the subjects on each of six "key 

result areas" indicated that they "exceeded the 

job requirements." Most other appraisal methods in use when the present study was being 

planned were, like those at the time of the 

ARTCC study, designed primarily for remedial 

and diagnostic purposes and/ or were not uniform 

from facility to facility. Moreover, the operationally derived evaluations of performance were 

not expressed. in quantitative terms and were 

generally not amenable to quantification. Thus, 

the first major efforts in preparing for the current study focused upon the development of experimental procedures with which to obtr1-in reliable, subjective, · quantitative ratings of job 

3 

performance at the journeyman TATC ATCS 

level. 

N AFEC ATCS personnel, instructors in the 

FAA Academy's basic TATC training course, 

CA:\II researchers, and ATS officials contributed 

to"·ard deYelopment of the A TCS Performance 

E,·aluation Form. The instrument, a copy of 

which appears as Appendix 1. embodied a seYenpoint rating scale and listed 29 elements, or 

aspects of performance for e\·aluation. The first 

section of the instrument dealt with the technical 

aspects of TATC work. It. was de,·eloped, as 

mentioned earlier, by controller-oriented personnel. se,·eral items in this section represented 

original formulations but some were ,-ery similar 

in content and wording to the ';performance 

indicators" (i.e., appraisal standards) specified 

by the FAA in its procedures for the officia l semi-annual "O,·er-the-Shoulder Rating" 

("OSR") of each ATCS. (The official OSR's 

were not included in the present study because 

they were not amenable to quantification.) 

Through ·use of the rating scale, the subjects 

were rated on each item, or element, of the first 

section; first, with respect to Radar ( R) control 

and then, on the same items, with respect to 

Local (L) control. 

Eight items, extracted from eYaluation instruments previously deYeloped and used by CA:\II 

for experimental purpo;;es only, comprised the 

next section of the rating form. The section 'vas 

entitled "General Related Elements of ATCS 

Performance~ ' and pertained to teamwork, tactfulness, interest and effort toward self-impro,·ement, adaptability to changes in procedures and 

policies, and the like. 

The rating scale for the eight ';G" (General) 

elements of performance was the same as for the 

"R" and "L" items. It consistPd of se\·l'n categories: "inadequate,' ' "marginal," "below :n·erage," ''average (or good),'' "n r:; good,'' 

"excellent,'' and "outstanding.'' Printed instructions requested that the Haluator try ro be 

realistic in his e\·aluations and. insofar as possible, rate the ATCS with respect to performnnce 

rendered during the Lu~iPst, or peak-trafli.c. 

periods. For analysis purposes, each rating 

reflecting "inadequate·· performance " ·as coded 

as "1," "marginal'' as "~:· and so forth. with 

"outstanding" being assigned a code of "7.'~ 

The last section of the instmment consisted of 

a single item which read, ';Use the scale belovr 
to rate tl1e ot'r'ndl profici ency of this controller 

t·datit·c to all the r:outrullers yon haN; !.·no1J)n." 

Se,·en response categories were provided: "Hottom 1 O%," "L()\\"l~r lntennediate 15%," "Lower 

,\Iiddle Hi %,'' '','\Iiudle :20%," "Upper ~1iJJle 

Ui %," "Upper lntenneuiate 15%," and "Top 

lll%." The evaliwtion of each suujeet on this 

item, referreu to as the l{e]ative (H) Hating, was 

also (:oded in terms of the same JUUnerical scale 

discussed above, with a code of "1" indicating 

the lowest category, "2" tl1e next, and so forth. 

P erfO'JmaJu.·e Natiugs by 8upe1·visun, Crew 

ki f~ , a11d Peers. The Facility Chief and other 

staff memuers at each of the 17 towers cooperated 

in ananging work schedules whereby virtually 

all journeyman-leve l ATCSs, their Crew Chiefs, 

and Supervisors received an oral briefing concerning some of the major objectives of the proposed research and the need for certain types of 

data and information. They were told that the 

01·entl I ou jecti ,.e of the study was to identify 

and assess tl1e relati1·e importance of factors 

bearing upon ATCS performance. The rating 

form wa s reviewed and discussed in conjunction 

with the explanation that it was desired that 

each controller's level of proficiency be established on the basis of ratings by one to two 

Supervisors, one to three Crew Chiefs, and also 

fi ,.e or more peers-- preferably members of the 

crew with whi ch the controllers worked most 

frequently. 

It was pointed out that a person's knowledge 

of the job, previous training, experience, health, 

and age presumn bly represented only a few of 

the possible determinants of individual performance. 'Vorking conditions, administrative policies, and work-shift patterns and changes were 

also mentioned as ueing of likely import. Efforts 

to preclude bias in the study were made by trying to conchtct. each briefing session so that age 

and experirn. , rece i1·ed no p<.~rti ular emphasis. 

The 1·isiting me1nber of the research team requested that, in addition to their ratings of several coworkers, the controllers (only) also 

C'Omplete two questionnaires. It was explained 

that one of the two was aimed at obtaining firsthand information from jonrneymen regarding 

whnt they liked best and disliked most about 

their job and work environment, and also brief 

descriptions of other faetors ancl circumstances 

" ·l1i ch they felt might inflnence pedormance·-

either at their fa('ility of assignment or in ATC 

4 

work in general. (Findings relating to these 

att i t.JH.Ies and rnoti vat ional factors in TATC 

work have already l1een reported. 8 ) The other 

questionnaire whid1 tlw journeymen only were 

asked to mmplete was the "Personal Background 

and Data Sheet." It. was designe.d to elicit such 

information as entry-on-duty (EOIJ) with the 

FAA, types and amounts of ATC experience, 

breaks in ATC service (including all jobs not 

involving aetna! control of air traffic), facilities 

of assignment during eareer, promotional dates, 

l>irthdate, and Social Security Number. Data 

of certain types, and parti cularly age and FAA 

ATC experience, were later verified against information whicl1 management officials extracted 

from tl1e personnel file in response to a brief 

qnestionnaire they were asked to complete. 

ltating tlte Helati.'t:e Importance of Performanr:e-Hating-Fmm It em~ . The fifth instrument 

developed for the study embodied a five-point 

rating scale, included a listing of every item 

(i.e., element) of the ATCS Performance Evaluation Forrn, and contained instructions which 

read, " ... indicate the relative importance with 

which you think each element should be considered in the job performance evaluation of a 

journeyman controller at this facility." The five 

response categories, pertaining to relative importance, were: "None," "Little," "::\Ioderate," 

"Considerable," and "Extreme." The initial 

research design specified that every person rating 

one or more of the ATCSs would also be requested to complete one copy of the itemimportance rating form. Such a procedure 

would have permitted analyses to determine the 

appropriateness of " ·eighting the coded rating 

of an ATCS on each performance item in terms 

of his evaluator's respective item-import rating. 

However, prior to finalizing arrangements for 

visits to the facilities, ATS and CA~II reviewed 

all aspects of the study with respect to minimizing the time and efl'ort required of all participant!' and subsequently decided that ratings of 

the items should be collected from supervisory 

personnel only--nnd on a strictly voluntary, or 

"time-available," basis. 

Collection of Job Ratings and Other Data. 

In discussing the .-arious types of information 

which controllers, Crmv Chiefs, and Supervisors 

" ·ere being asked to proYide, the briefing officer 

stated that all material would be treated in a 

confidentinl manner, used solely for research 
purposes, and destroyed as soon as all analyses 

were completed. They were informed that participation in no phase of the study was mandatory. The fruitfulness of the study, it was 

explained, would depend upon their willingness 

to participate as requested, their efforts to be 

"realistic" in evaluating individual ATCS performance, and the degree of success achieved in 

the collection of detailed and accurate personal 

background data for all journeymen. 

Copies of the ATCS Performance Evaluation 

Form were distributed within each facility on 

the basis of name listings and work-shift schedules provided by management officials. Journeymen controllers who most frequently worked 

together as a crew (or team) were asked to rate 

each other unless they personally objected to 

doing so or felt that for any reason they could 

not validly assess an individual's performance. 

Most crews, with exception of the Crew Chief, 

consisted of five journeymen, but some were comprised of six to eight. ·when a controller was 

known to ha,·e appreciable work experience with 

more than one crew, the Facility Chief or his 

assistants, designated those ATC:Ss who, in their 

opinion, could render the most reliable peer ratings. Inasmuch as the recent work experience 

of a typical Crew Chief was seldom restricted 

to one crew, each \vas usually requested to rate 

the performance of ATC::3s of two or more crews. 

Facility management officials also designated the 

ATCSs whom each Supervisor should emluate. 

Researchers had anticipated that arrangements 

could be made permitting each ATCS to be rated 

by at least. one, and preferably two, of the Supervisors. At many facilities, however, no attempt 

was made to collect dual supenisory ratings on 

the ATCSs because weather conditions, traffic 

loads, or other circumstances were such that officials deemed it inadvisable to do so. 

Although the journeymen controllers and Crew 

Chiefs were generally receptive to the proposal 

that they, rather than Supenisors alone, were 

to render ATCS ratings, some appeared rather 

apprehensi,·e about participating in the project 

until told that the completed rating forms could 

be submitted on an anonymous basis-that is, 

with no signature affixed. Howe,·er, they were 

also informed that some of the scheduled ana lyses 

were to focus upon comparing and correlating 

the ratings obtained from control personnel of 

the three respecti ,.e levels and that the need for 

separation of the data, with respect to source 

level, required that procedures especially designed 

for the purpose be employed in the distribution 

and collection of the rating forms. 

Only those copies of the rating form bearing 

the notation "By Supervisor" were given to the 

Supervisors; copies labeled "By Crew Chief" 

were provided each Crew Chief, and others, also 

appropriately designated, were distributed to the 

controllers of journeyman status. The research 

team member and facility management officials 

had predetermined the individual ATCSs whom 

each Supervisor, Crew Chief, and controller 

should rate and, as a precaution against an eval- · 

uator erroneously completing two rating forms 

for any given subject, each was provided no 

extra copies of the rating form (i.e., no more 

than the number of designated ratees}. It was 

requested that the rating forms and questionnaires completed by each participant be retumed 

directly to the visiting research team memberwho, in mos~ instances, remained at a facility for 

three or more days. Two large manila envelopes 

were furnished each participant for return of 

the various forms. In every briefing session, it 

was stressed that any individual who desired to 

remain completely anonymous with respect to his 

ratings of ATCSs should utilize both envelopes, 

using one for the return of the unsigned rating 

forms and the other for the questionnaires and 

forms on which his name appeared. In pointing 

out that the use of a single envelope for return 

of all materials by an individual would be interpreted as indicating declination of the anonymity privilege, the briefing official also restated 

that all data and material would be treated confidentially and used for research purposes only. 

III. Results and Discussion. 

5 

The Total., Sample 

Records re,·ealed that a total of GH controllers 

were \YOrking within the 17 TATC facilities at 

the journeyman level. At the time the survey 

was conducted, the normally prescribed pay 

grade, in terms of the General Schedule ( GS), 

for an ATCS who had met all qualification requirements for working all control positions in 

a Level-III TATC facility was GS-12. Of the 

61± subjects, 609 '"ere GS-12's; the remaining 

fhe were GS-ll's whom supervisors indicated 

were fully qualified for promotion. 
Visits to the facilities for collection of job 

performance ratings and other data were made 

during November 1968 through February 1969. 

The specific date on which the data were obtained for each ATCS was used in determining 

his chronological age and length of FAA A TC 

experience. Due to an error, information relating to age and experience was not obtained for 

one individual and, as a consequence, several 

analyses were based on 613 eases rather than 614. 

Age was recorded in years, rounded to nearest 

birthday, whereas experience was recorded in 

months. The two youngest subjects were 27 

years of age, the oldest was 64, and the mean age 

Table 1. Frequency distributions of chronological age and FAA ATC experience 

for 613 journeyman-level ATCSs of 17 high-IFR-traffic-density TATC 

facilities. 

Chronological Age FAA ATC Experience 

Age Per Cent Exp. Per Cent 

(Years~ N of Total (Months) N of Total 

60 & > 1 .16 252 & > 13 2.12 

59 246-251 3 .49 

58 2 .33 240-245 1 .16 

57 1 .16 234-239 3 .49 

56 228-233 

55 1 .16 222-227 2 .33 

54 3 .49 216-221 2 .33 

"53 210-215 3 .49 

52 3 .49 204-209 2 .33 

51 10 1.63 198-203 1 .16 

so 4 .65 192-197 5 .82 

49 5 .82 186-191 1 .16 

48 9 1.47 180-185 4 .65 

47 2 .33 174-179 2 .33 

46 10 1.63 168-173 1 .16 

45 13 2.12 162-167 3 .49 

44 8 1.31 156-161 4 .65 

43 10 1.63 150-155 21 3.43 

42 5 .82 144-149 40 6.52 

41 8 1.31 138-143 74 12.07 

40 21 3.43 132-137 41 6.-69 

39 45 7.34 126-131 29 4.73 

38 32 5.22 120-125 39 6.36 

37 45 7.34 114-119 115 18.76 

36 62 10.11 108-113 46 7.50 

35 66 10.76 102-107 47 7.66 

34 43 7.01 96-101 25 4.08 

33 52 8.48 90- 95 17 2.77 

32 61 9.95 84- 89 12 1.96 

31 58 9.46 78- 83 9 1.47 

30 21 3.43 72- 77 15 2.45 

29 9 1.47 66- 71 19 3.10 

28 1 .16 60- 65 5 .82 

27 2 .33 59 & < 9 1.47 

Total 613 100.00 Total 613 100.00 

6 
for the 613 for whom birthdates were obtained 

was 36.5 years. Experience for the 61!1 ranged 

from 27 to 3-!5 months and aYerag-ed 125.0 months 

( 10.42 years). The distributions of age :md experience appear in Table 1. 

A total of 4,42!1 ATCS Performance Eraluation Forms were completed for the 61-! subjects; 

697 of the 4,423 were submitted by Supen·isors, 

885 by Crew Chiefs, and 2,841 by journeyman 

controllers. Prior to coding and processing, the 

forms were sorted to determine the number recei ,·eel by each controller from personnel of the 

three different leYels. It \Yas ascertained that 

each of 576 of the 61-! was rnted by one or more 

of the 78 Supenisors, 59-! by one or more of the 

117 Crew Chiefs, and 609 by one or more of the 

614 journeymen. Some 455 of the ATCSs recei Yed only one superYisory e,·a I nation, 121 recei ,·ed two, and 38 none. Twenty recei ,·eel no 

rating by a Crew Chief, 370 were rated by one, 

157 by two, and 67 by three Crew Chiefs. Only 

fh·e controllers failed to be eya]uated by at least 

one peer, ''"hereas 16 were rated by one, 39 by 

two, 120 by three, 1-!6 by four, and 288 by fh·e 

or more of their colleagues. 

The initial step in processing each ATCS Performan Evaluation Form im·oh·ed coding, or 

quantification, of the ratings. As pointed out 

earlier, an evaluation of '·inadequate" on an item 

of performance was coded as "1/' "marginn l" as 

"2," and so forth, ''"ith "outstanding'' being assigned a code of "7." The midpoint on the descripth·.e scale 'vas "ayerage (or good)~" which 

corresponded to a quantitatiYe, or coded, rating 

of "-!. ~' 

Dealing first with the forms submitted by 

Supervisors, the coded ratings of each controller 

on the 20 aspects of Radar Control ''"ere tallied 

for each form, summed for both forms when 

rated by two Supen·isors, and then di ,·ided by 

the number of element ratings comprising the 

sum, to obtain an a ,·erage referred to as the 

subject's "Mean Supen·isory 'R' (Radar Control) 

Rating." Similar techniques were used to determine each controller's "Mean Supenisory 'L' 

(Local Control) Rating ,~~ "l\Iean Supen·isory 

'G' (Genernl) Rating," and "~fean Supenisory 

'R' (Relati,·e) Rating.'~ The fonr ,·alues were 

then averaged to obtain each subject's "~fean 

Supervisory 'RLGR' Rating." The same procedures were employed to determine the mean R, 

7 

L, G, R, and RLGR Ratings of the controller 

by his Crew Chief ( s) and also corresponding 

means of ratings by his coworkers~ or peers. 

Lastly~ fi Ye summary measures of performance 

were deriYed for each ATCS by aYeraging the 

means of ratings rendered by the Supen·isors, 

Crew Chiefs, and Cmvorkers. They were designated as the "O,·erall Radar/~ "O,·erall Local," 

'·O,·erall General~~· "0Yerall RelatiYe Proficiency," nnd "Cherall RLGR" ratings. 

R e1iabi1ity of RLGR Ratings. Inasmuch as 

the rating forms were unsigned, dual ratings 

receiYed by each ATCS from personnel of each 

source lnel were arbitrarily designated as the 

"first'' and "second" and other multiple ratings 

as the " third.'' "fourth," •'fifth," and so forth. 

Identification of the somce ]eye] wns maintained 

so as to permit computation of the (Pearson 

product-moment) correlations between the sets 

of ratings. Although not shown in any table, 

the correlations between the RLGR ratings by 

co,vorkers rang-ed from .21 to .-!7 and, through 

use of z-coefficient transformation techniques. 

were found to ayerage .39. The correlations between the first Yersus the second and third Cre"· 

Chief RLGR Ratings were .-!5 nnd .5-!, respectiYely, .-!0 behveen the second and third, and the 

:werage of the three was .-!6. The RLGR Ratings of the 121 ATCSs by hvo different SuperYisors correlated .62. Although none of these 

coefficients should be regarded as exceptional, 

most of them are \Yithin the range of those generally reported in the open scientific literature 

for studies im·ohing job performance ratings of 

personnel in ,·arions occupationnl specialties:' 7 n P 

En1-p-ilvical / nfel'l'e1ationships of Aqe, Ea'JI('I'-

ience, and RLGR Ratings. The intercorrelations 

of the Supen·isory, Crew Chief, and Peer RLGR 

Ratings, the Q,·erall RLGR Ratings, and the 

empirical relationships of th four criterion 

measures to both Chronolog-ie a l ge. a ,,t I_rngth 

of FAA ATC Experience. are shown in Table~­

(All correlation coefficients. or "r's," appl'aring 

in the table are of the Pearson product-moment. 

type; the same is true with respect to the r·s 

presented in all snhseqnent sections of this report 

except where otherwise noted.) The ::\[ean Su· 

petTisory RLGH Ratings correlated .5M with 

those of the Crew Chiefs and .59 with those of 

the journeymen AT( '~s, wlwreas the latter correlated Ji6 "·ith those based on Crew Chief 

en1hmtion. 
00 

Table 2. Intercorrelations of RLGR ratings rendered by Supervisors, Crew Chiefs, and ATCS 

and correlations of ratings with age and FAA ATC experience. 

Crew Team Overall Chrono

. 

Chiefs Peers Average Age 

Max. N N N N 

N Mean S.D. r r r r 

Composite RI.GR 576 5.13 .88 558 571 576 576 

by .58 • 59 .86 -.3

RI.GR 594 5.29 .85 589 594 593 

by Crew Chiefs .56 .85 -.3

Composite RI.GR 609 4.99 .71 609 608 

by Team Coworkers .83 -.4

Overall RI.GR, Avg. of 614 5.14 .68 613 

Supv., Chfs., Peers -.4

Chronological 613 36.50 5.49 

Age 

Months of FAA ATC 613 124.97 38.30 

Experience 

*All correlation coefficients are statistically significant at the .01 level. 
The Overall Average RLG R Rating correlated 

.86, .85, and .83 with the Mean RLGR Ratings 

of the Supervisors, Crew Chiefs, and Coworkers, 

respectively. Low but statistically significant 

(p< .01) and negative r's, ranging from -.23 to 

- .29, were obtained between Experience and the 

four criterion variables. Although a positive 

correlation of .63 was found between Age and 

Experience, the inverse relationship of Age to 

each of the four performance measures was significantly (p < .05) greater than obtained for 

Experience. Age correlated - .36 with the Mean 

Supervisory RLGR Rating, -.34 with the corresponding composite Crew Chief rating, -.42 

with the Mean Coworker RLGR Rating, and 

-.44 with the Overall Average RLGR Rating. 

While these coefficients are of substantial magnitudes and all statistically significant (p < .01), 

they should be regarded as grossly attenuatedas should those pertaining to length of experience. Almost 88 per cent of the A TCSs were 

between the ages of 27 and 44 and a bout 92 per 

cent also had less than 156 months (i.e., under 

13 years) of experience in FAA ATC work. 

Such restriction-of-range effects indicated the 

need for other analyses whereby the means of 

the performance ratings could be ascertained and 

compared for the ATCSs of various age and 

experience groupings. 

Means of RLGR Ratings by ATOS Age Group. 

After reviewing the age distribution (Table 1), 

the investigators divided the sample into six subgroups for a series of analyses aimed at determining the extent to which the•performance rating means might vary in accordance with chronological age. The first of the six consisted of 

the 33 subjects of age 30 and younger; the next 

four were the five-year age intervals, "31-35," 

"36-40," "41-45," and "46-50," which contained 

280, 205, 44, and 30 cases, respectively; the sixth 

category, "51 and older," contained the remaining 21 cases. Averages of the ~Iean RLG R 

Supervisory Ratings for the subjects in the 

various age brackets were computed and plotted. 

The same procedure was employed with respect 

to the Mean Crew Chief RLGR Ratings, the 

Mean Coworker RLGR Ratings, and the 0\·erall 

RLG R Ratings. The results are presented in 

Figure 1. 

In examining Figure 1, it should be noted that 

the plotted means of the four criterion measures 

all follow a similar pattern; they indicate that 

9 

the ATCSs of age 30 and younger generally received slightly higher ratings than those of age 

31-35 or 36-40, and that the controllers within 

each succeeding age bracket tended to receive 

progressively lower mean ratings. A one-way 

analysis of variance (ANOVA) of the o,·erall 

RLGR Ratings and ANOVA~s of RLGR ratings 

rendered by control personnel of each of the 

three different le,·els all yielded significant Fratios, indicating the presence of statistically 

significant differences between the means of ratings (of each type) for two or more of the age 

subgroups. It was subsequently determined, 

through use of Scheffe's6 "S-~fethod" that the 

means of each of the four criterion measures for 

ATCSs of age 30 and less, 31--35, and even those 

of age 36-40, were significantly higl1er than 

those obtained for controllers of age 46--50 or 51 

and older. Moreover, the ATCSs of age 41-15 

received significantly lmver mean ratings from 

both their Crew Chiefs and Coworkers than did 

ATCSs of either of the two youngest subgroups 

and their mean Overall HLGR Rating also differed significantly from those of both younger 

subgroups. 

A finding of incidental iuterest was that the 

means of the ratings rendered by the ATCSs 

were consistently lower, but generally not significantly lower, than those of the Crew Chiefs 

for controllers of eYery age bracket, and also 

lower than those of the Supervisors for all except the two oldest subgroups of controllers. 

Means of the Crew Chiefs ratings were higher 

than those of the Supervisors for five of the six 

subgroups, with the greatest differences, which 

were not statistically significant, pertaining to 

the ATCSs of age 46-50 and 51 and older. 

(Except where otherwise noted, all mean differences discussed in this and s11cceeding sections 

of the report were tested fo r statistica 1 significance by Scheffe's method.) 

The question as to whether the ages of the 

raters may have influenced their ratings of differentially aged A TCSs prompted t hrce ann lyses : 

one each on the ratings rendered by Supervisors, 

by Crew Chiefs, and Coworkers. (The results 

are presented in Appendices 2, :~, and 4.) Each 

such analysis was, by necessity, restricted to the 

data of only those raters who declined the anonymity pri,·ilege (i.e., those who signed their 

eYalnation forms). In the first analysis, 381 

completed rating forms for a total of 2SO ATCSs 
..... 

0 

5. so -t 0 ----0 

- ratings by 

• - _, -- crew chiefs -0 

crew ch

RLGR i 

- ·········- ' 

ratings h y • •.•.. 

6 twc ra i 1 R

super v is 

5 00 -1 cow0rk c rs ·· · . 

... ' cowor «

·. 

a 

1 

. 

Rating 

4 -50 -1 . . ' 

. . ' 

., • ' 

Average i . b \ . . c rat1ngs y ·. · 

I 

supe r vis ors' over

4.00 j 

I I I I I I 

Chronological Age 30 & < 31-35 36-40 41-45 46-50 51 & > 

N - by supv s , 30 262 192 43 29 20 

Mean rating 5.38 5.30 5al6 5.02 4.17 3.97 

SaD, . 62 .82 .83 , 79 .82 • 91 

N - by crw. chfs , 33 269 200 42 29 20 

Mean rating 5.50 5 a46 5.32 4.86 4.64 4.21 

S.D a .64 .80 .79 .85 .92 .87 

N - by coworkers 32 276 205 44 30 21 

Mean rating 5.22 5. 18 4.98 4.64 4.29 4.00 

SoD a .53 a65 .66 .70 .58 .67 

N - Overall 33 280 205 44 30 21 

Mean rating 5.38 5. 31 5.15 4.85 4.37 4.07 

SaD a . 46 .62 .62 ,66 .61 .67 

FIG URE 1. Means of RLGit job performance ratings by age level for Terminal ATCSs evaluated by supervisors, crew chiefs, and journe

total of 121 ATCSs were rated by two super visors rather than one; 224 were rated by two <"rew chiefs and 67 by three crew ch

by at least two coworkers, and 288 of the 593 were rated by five or more colleagues. 
were identified as originating with 41 Supervisors. Ninety of the ;)81 were from 1 () Supervisors of age 4;) and younger, l;)± originated 

with 17 who "-ere 46-50, and 137 were from 14 

of age 51 or older (Appendix 2). Xo significant 

or appreciable differences "·ere found between 

the means of the ratings rendered hy Supen·isors 

of the respectiYe age categories for ATCSs 

within any of the age groupings, "R!i or younger,'' 

"36-40," "41-45," and "46 or older.'' In eontrast. 

a corresponding analysis of 5±5 Crew Chief 

RLGR Ratings re,·ealed that the raters of age 

40 and younger tended to rate the ATCSs of age 

41-45 and 46 and older some"·hat lower than did 

the Crew Chiefs of age 41-45 and appreciably 

lower than the raters of age 46 and older (Appendix 3), but the mean differences were not 

statistically significant. Moreover, an analysis 

of 654 Coworker RLGR Ratings yielded results 

(Appendix 4) which, like those of the Supervisors, demonstrated no general relationship between the ages of the raters and their evaluations 

of the relatiYely young or elder groups of ATCSs. 

/Jfeans of RLGR Ratings by FAA ATO Experience Groupings. In order t o assess the relationship between Length of FAA ATC 

Experience and ATCS performance, the sample 

was divided into eight subgroups, with each subgroup having ATC service within a specified 

range. The first category, designated "less than 

five years," included only nine cases. Fortyeight subjects who had FAA ATC work of at 

least 60 months but less than 84 months (seven 

years) were categorized as having "5-6" years. 

The next three categories, "7-8," "9-10," and 

"11-12," contained 101, 229, and 176 cases, respectively. Inasmuch as only 50 subjects possessed experience of 156 months ( 13 years) or 

more, 21 were grouped in terms of the fonr-year 

interval "13-16," 16 were designated as having 

"17-20," and 13 as having "21 or more." Averages of the Mean Supervisory RLGR Rntings 

were then computed and plotted and the procedures were replicated with respect to the :.\lean 

Crew Chief RLGR Ratings, the :.\lean Coworker 

RLGR Ratings, and the 0Yerall RLGR Ratings. 

The results are shown in Figure 2. 

Figure 2, as did Figure 1. reflects a high degree of congruency between the patterns of the 

plotted means of the fom criterion measures. 

(Although the Crew Chiefs tended to rate the 

controllers of most experience subgroups somewhat higher than either the Supen-isors or the 

Coworkers, the only differences which proved 

statistically significant were between the means 

of the Crew Chief and Co"·orker ratings of those 

ATCSs haYing 9-10 or 11-12 years experience.) 

The figure illustrates that the Supen-isors, as 

well as the Crew Chiefs and journeymen, generally rated the controllers haYing 5-6, 7-8, or 

11-12 years of sen-ice slightly higher than those 

having less thnn five years of experience and 

appreciably higher than those ha,·ing 13-16, 

17-20, or 21 or more years. Although these findings did not stem from a longitudinal study and, 

as will be discussed later, are also confounded 

to some extent by age effects, they nevertheless 

suggest that significant decrements in performance are apt to occur at about the 13th year of 

many of the TA TC controllers' careers. 

11 

An analysis of variance of the Overall RLGR 

Ratings yielded a significant F -ratio and it was 

subsequently ascertained, by Scheffe's technique, 

that the mean performance level of each of the 

three niost experienced subgroups differed significantly (p<.05 or better) from the means 

established for ATCSs who had 5-6, 7-8, 9-10, 

or 11-12 years of service, whereas none of the 

mean differences which involved the least experienced subgroup (i.e., less than fi,·e years) 

proved statistically significant. 

Significant F-ratios were also obtained in 

ANOV A's of the ratings rendered by control 

personnel of each le,·el. The Supen-isors rated 

the ATCSs who had oYer 20 years of service 

significantly lower (p<.05) than all other subgroups. Other significant mean differences with 

respect to the Supenisory eya]nations pertained 

to the subjects with 17- 20 years experience Yersns 

those having 5-6, 9-10. or 11-12 years, and eontrollers with 13-16 years experience n:-rsus those 

'"ith 5-6 or 9-10 years. Morerp;er. ti ;. ]Jrobability of chance occurrence of dift'erences such as 

between the menns of the Supenisory ratings 

of ATCSs haYing 17-20 years experience and 

those haYing either 7-R or 11..,.12 years was fonnd 

to be less than 10 in 100 (i.e., p<.10). The 

Crew Chiefs tended to rate the controllers of the 

two most experienced subgroups significantly 

lmYer than those haYing fl-6, 7-8, 9-10, or 11-12 

years service. The snn1e. was tnie with respect 

to the ratings rrnderPd by Coworkers: howeYer, 

the latter also tended to rntr the controllers of 
...... 

tV 

0 - ...... ....... 0 ' --o--- ' 

. b 1 • ' ....... 

o crew 

Rl.GR supvs. ::::::.: .:::::::::S • ._...__ • ' ratings by over

• • . . • 

• · • · • • ·· ' crew chiefs sup

'· .· . . . . . ' 5 . 00 • . .;· ·" w ' co

I 1 ratings by • ' 

0 

coworkers 0 

Rating • \ \ 

\ 

4.50 ·. . \ · .• "' 

. \ 

)If • --- 0 

Average ·· • • • • • • • 0 • 

• '' ''" ' 

Yrs. of FAA-ATC Exp. > 5 S-6 7-8 9-10 11-12 13-16 17-20 21 

N - by supvs. 8 45 96 213 165 21 16 12 

Mean rating 5.09 5.31 5 . 15 5.24 5.18 4.46 4.30 4

S.D. .79 .69 .91 .82 .85 .93 1.06 

N - crw. chfs. 9 48 96 219 172 21 15 13 

Mean rating 4.80 5.40 5.34 5.44 5.28 4.88 4.20 4

S.D. .64 .69 .89 .75 .86 1.02 1.00 

N - by coworkers 9 45 99 229 176 21 16 13 

Mean rating 4.91 5.15 5.19 5.06 4.98 4.29 4.15 4

S.D. .SO .58 .70 .66 .66 .87 .83 

N - Overall 9 48 101 229 176 21 16 13 

Mean rating 4.93 5.30 5.23 5.24 5.15 4.55 4.24 

S.D. .49 .52 .70 .60 .67 .82 .89 

FIGURt: 2. Means of RLGR job performance ratings by FAA ATC experience level for 'l'erminal ATCSs evaluated by supenisors, crew 

men coworkers. A total of 121 ATCSs were rated by two supervisors rather than one: 224 were rated by two crew chiefs and 67 

593 were rated by at least two coworkers, and 288 of the 593 were rated by five or more colleagues. 
the 13-16 year category significantly lower than 

those having 5-6, 7-8, 9-10, or 11-12 years experience. 

Interaction Effects of Age and E xperience. 

Inasmuch as the vast majority of the subjects 

were relatively young and few possessed lengthy 

experience in FAA A TC work, many types of 

analyses (such as two-way ANOVA's, correlational analyses, and other procedures) were inappropriate for determination of the interaction 

effects of age and experience upon performance. 

The procedures selected for the purposes were 

therefore rather simple. First, the group was 

dichotomized with respect to length of experience 

in order to compare the performance rating 

means of the two subgroups by age level. Secondly, corresponding procedures were employed 

wherein age was dichotomized to permit a comparative study of the performance of the two 

subgroups within and across experience levels. 

Several series of analyses involving different 

"cuts" for dichotomizing age and experience 

were accomplished. However, results are presented in this report for only those analyses in 

which the cutting points were bet,Yeen 40 and 41 

on age and between 12 and 13 with respect to 

experience. Only 95 ( 15.5 per cent) of the 613 

A TCSs were 0\·er 40 years old and no more than 

50 (8.2 per cent) possessed experience of 13 years 

or more. Other similar analyses in which higher, 

as well as lower, cutting points were employed 

yielded results which were considered less reliable and meaningful due to the small numbers 

of cases in the upper or lo\Yer categories of age 

and experience. The same was also true, and in 

greater degree, regarding the results of analyses 

in which three categories each were established 

for age and experience. 

A. Perfo?·nwnce of Dichotomized Age Groups 

by Experience L evel. Figure 3 presents the 

means of the 0Yerall RLGR Ratings of controllers within each of several age groupings who 

had FAA ATC experience of "12 years or less" 

and those who had "13 years or more." The six 

youngest of the 50 most experienced A TCSs \Yere 

36-40 years old. Their mean performance rating was slightly higher than that of the 199 

less-experienced journeymen of the same age 

bracket. However, those of the upper experience 

category who were 41-45 tended to be rated significantly (p < .01) lower than those of com par13 

able age in the lower expenence category. 

ProgressiYely lower mean ratings were receiYed 

by the controllers aged 46-50 and 51 or older of 

each experience category but the mean differences, though not statisticDlly significant, fa,·ored 

the ATCSs who had been in FAA ATC work 

no longer than 12 years. 

B. Performance of Dichotomized Experience 

Groups by Age L e1'e1. Figure 4 shows the means 

of the Overall RLGR Ratings by experience 

level for the dichotomized groups of ATCSs aged 

"40 and younger" and "41 and older." Before 

comparing the means of the two age groups, it 

should be noted that none of the younger personnel possessed experience greater than 16 years, 

whereas all but two of the 95 ATCSs of age 41 

and older had at least seven years. Sixteen of 

the 95 had 17-20 years service in the air traffic 

management system and 13 had 21 years or more. 

As may be recalled, a correlation of .63 (see 

Table 1) was obtained between age and experience for the total group of 613. 

Figure 4 illustrates that the younger controllers of every experience level tended to receive 

higher performance evaluations than those of 

age 41 and older. \Vith one exception, the means 

of the ATCSs of age 40 and younger were remarkably similar across all experience levels. 

The exception pertained to the younger controllers who had less than fh·e years ATC service. 

Their mean rating was somewhat lower than 

that of the more experienced personnel of the 

same age category, yet slightly higher than the 

aYerage of ratings receiYed by the two controllers over 40 yea rs old "·ho also had less than fiye 

years experience. A comparison of the rating 

means of the ATCSs aged 41 . and older by experience level indicated that those of the 9-10 

year leYel tended to receinl the highest ratings, 

that those with 11-12 years were rated substantially lo\Yer than the latter, and that the three 

lowest rating means pertained to those who possessed either 13-16, 17-20, or 21 or more years 

experience. A matter of far greater importance 

is that all differences behYeen the rating means 

of the differentially aged subgroups favored the 

younger controllers. The largest mean difference 

(p<.Ol) pertained to those ATCSs having 13-16 

years experience, Iii of whom were 41 or older 

and six of whom represented the most highly 

experienced of all the younger controllers. The 
...... 

H'-

Overall 

5.00 

RLGR 

4.50 ... 

Rating 

4.00 • 

Chronological Age 

N - 12 years & less 

Mean 

S.D. 

N - 13 years & more 

Mean 

S.D. 

N - comb. exp. grps. 

Mean 

S.D . 

. 

·------

combined -. 

exp. groups 

12 years 

or less 

comb. 

30 & < 

33 

5.38 

.46 

33 

5.38 

.46 

31-35 

280 

5.31 

.62 

280 

5.31 

. 62 

\ 

36-40 

199 

5.15 

.62 

6 

5.26 

.67 

205 

5.15 

.62 

• 

\ 

\ 

0 

........ . 

13 years', 

or more o 

FAA ATC ' , 

experience ' • 

........ 

0 

41-45 46-50 51 & > 

28 18 5 

5.04 4.46 4.39 

.62 .60 .38 

16 12 16 

4.51 4 . 24 3.97 

.61 .62 .72 

44 30 21 

4.85 4.;37 4.07 

.66 . 61 . 67 

FIGURE 3. Means of Overa ll RLGR Ratings by age level for Terminal ATCSs of dichotomized FAA A'l'C experience groups "12 years 

or more." Disregarding experience, differences between the mean r atings of each of the following groups are significant (P<-05

30 and younger or 31-35 versus those either 41-45, 46-50, or 51 and older; those of age 36-40 versus those either 46-50 or 51 and 

41-45 versus the oldest group. Of the differences between experience subgroups within age levels, only that for ATCSs of age 4
...... 

Ql 

age 40 

• 

---

; 

& younge.r Overall • - Age 

./ . combined .... ..... comb . 

age grouos s.oo 0 

• / ' / / ' 0 ------ / RLGR 0 ' ' 0 

' • Age 

4 , so age 41 ' " ' & older ' Rating 0 ---. - - . 

Years FAA-ATC Exp. < 5 S-6 7-8 9-10 11-12 13-16 17-20 21 & > 

N - Age 40 & < 7 . 48 95 210 152 6 

Mean 4.97 5.30 5.26 5.26 5 . 23 5.26 

S.D. .so .52 .69 0 59 .63 .67 

N - Age 41 & > 2 6 19 24 15 16 13 

Mean 4.79 4.73 4.97 4.63 4.26 4.25 4. 20 

S.D. .67 .66 .66 .69 .89 .33 

N - Comb . age grps. 9 48 101 229 176 21 16 13 

Mean 4.93 5.30 5.23 5.24 5.15 4. 55 4.25 4.20 

S. D. .49 .52 .70 .60 .67 .82 .89 .33 

FJGL"m: 4. of Overall ltLGlt by FAA ATC experience level for 'l'em1iual A'l'CSs of dichotomb:etl "40 aut! yo

older." In comvnring the mean rating;; of the exverience groups, irrespective of age, differences are significaut (p<.05) for: A'l'CS

7-8, 9-10, or 11- 12 years of experience versus those having either 13-1G, 17-20, or 21 or more years. Ji'or age subgr·oups within t

eant pertain to with U-10, 11- 12, and 13-1G years experietwe. 
next l:trgest. (li fl'P-rCIH'C il1\·ol\-ccl tl1ose hnxing 

11-12 years experiPIIc·e; the 111can of the l!i~ subjects of the lower age catC'gory was signifieantly 

higl1er (7'< .01) than that of the 24 older and 

eomparably experienced ATCSs. The mean difference between the younger a11d older subgroups 

ha\·ing D- 10 years experience \\·as also signifi cnnt 

(p<.O:"i), whereas the two remaining differences 

(which involved relatively small numbers of 

older controllers) were not. 

C. Dominance of Aging over Experience Effects. The results presented in Figme 4, supplemented by those shown in Figure :1, illustrate 

that level of perfor11wnce in control work is more 

im·ersely related to (·.hro11ologieal age than length 

of A TC experience. The most highly ex perienced of the ATCSs of age 40 and younger were 

among those recei Ying the highest men n ratings. 

The findings conclusi\·ely demonstrate the presence of aging efl'ecls, with the effects becoming 

progressi\·ely more pronounced for those controllers of each age bracket beyond :~G---!0. " Tithin 

e\·ery subgroup 0\·er 40 years of age, those subjects ha\·ing ATC experience of 1:1 years or more 

received lmver mean ratings than those of the 

lower experience category; howe\·er, it should 

also be noted that most of the mean differences 

between the experience subgroups of each age 

level are relatively small compared to the differences between the rating means of the differentially aged subgroups of each experience level. 

These findings imply that decrements in ATCS 

performance are much more likely to occur as a 

function of aging and that, if control 'vork is as 

stressful as so commonly belie\·ed, the buildup 

of the presumed work-related stress effects is not 

apt to be reflected in the performance of a typical ATCS until he is at least ±0 years old. 

Other analyses, corresponding to those depicted 

in Figures ~ and -1, were accomplished on the 

Supel'l i;:,01} HLGR Ratings, the Crew Chief 

Ratings, and the Coworker RLGR Ratings. 

Findings obtained in each of the three sets of 

analyses (Appendices fi, 6, 7, 8, D, and 10) '"ere 

essentially the same as those discussed immediately nboYe for the composite 0\·erall RLGR 

Rutings. This being so, fmther analyses, wherein 

distinction '"oulcl ha \·e been maintained with respect to the performance measn res rendered by 

control personnel of the \·arious le\·els, \Yere not 

conducted. 

16 

The Overall R-Hadar Hatings, Overall L-Local 

i{atings, (herall 0-0eneral Hatings, and Overall 

H-Helati\·e Rntinf,rs were analyzed in the same 

manner as the 0\·erall HLGR Hatings. The results are depicted in Appendices 11, 12, 13, 14, 

15, lG, 17, and lH. Findings relating to three of 

the four different types of measures' were remarkably similar to those shown in Figures 3 and 4 

for the composite ratings of performance. Those 

relating to the Overall H-Helative Hatings also 

conformed to the general pattern of those of all 

previous corresponding analyses but were much 

more pronounced, or accentuated, further illustrating that: ( 1) the performance decrements 

were primarily associated with aging, and (2) 

the interaction efl'ects of age and experience were 

restricted to those controllers over 40 years of 

age. 

PeTformance H1·alnation8 Weighted in Terms 

of Item lm7Jort Ratings. Only supervisory personnel completed the Item Importance Hating 

Form. This instrument embodied a fiye-point 

scale for rating the "relati\·e importance" of each 

item of the ATCS Performance Evaluation 

Form. Sixty-eight of the 78 Supervisors who 

submitted evaluations on ATCS personnel also 

completed a copy of the Item Importance Rating 

Form. Analyses (not presented in this report) 

were undertaken in which each ATCS's rating 

on each performance element was weighted in 

terms of his Supervisor's respective item-import 

rating. Correlations were then obtained between 

the weighted and non"·eighted ratings, by item 

and groups of items, for the ATCSs of the separn te and combined facilities. The Yast majority 

of the coefficients were oYer .80; in fact, most 

were larger than .90 and some were greater than 

.95. Consequently, the contemplated analyses 

which were to have focused upon the relationships of age and experience to the weighted 

measures of performance were not undertaken. 

Facility Diff'erences 

Differences between the Yolumes of air traffic 

handled by the nrious facilities suggested the 

need for a facility-by-facility comparison of the 

interrelationships of chronological age, length of 

experience, and performance. Inasmuch as all 

pre,·ious analyses had yielded highly similar results for the different performance measures, it 

was decided thn t only one criterion variable, the 

Overall RLGR Rating, should be included in 
the correlational analyses. Although not dealt 

with in earlier phases of the study, age at entry 

into FAA ATC training ''"as also scheduled for 

inclusion. 

The intercorrelations of Training Entry Age, 

Age When Rated, Years of FAA ATC Experience, and performance (as represented by the 

composite RLGR measure) are shown in Table 3 

for the journeymen of the separate and combined 

facilities. The facilities are listed in order of 

IFR operations performed during 1969. 

Oorrelatire Data for Combined Facilities. 

Looking first at the results shown in the lower 

section of Table 3 for all 613 subjects, it should 

be noted that the correhltion between Trnining 

Entry Ap:e and Age 'Yhen Rated \Yas .81. This 

highly significant (p< .01) relationship suggested that many of the controllers who were 

relath·ely old at the time the suney was conducted may have begun their career in the air 

traffic management system nt a more adYanced 

age than the younger journeymen. This was 

verified by a biYariate frequency distribution 

which indicated that 32 (33.7 per cent) of the 

95 journeymen who ''"ere m·er -±0 years of age 

at the time the rating data were collected had 

. been 36 or older upon entry into FAA ATC 

training, tlwt 27 (2R.4 per cent) entered when 

31 to 35 years old, and that only ~6 (37.9 per 

cent) began their career before age ~1. As 

noted earlier, seYeral (' A:\fl follow-up studies1 2 4 10 12 13 14 of Academy entrants haYe shown 

that personnel older than ~0, nnd particularly 

those oYer 35, p:enerally tend to experience much 

greater difficulty than their younp:er colleap:ues 

in passing the Academy's basic training course 

and in successfnlly completing subsequent phases 

of training. Inasmnch as almost 72 per cent of 

the 95 oldest journeymen inYol 1·ed in the present 

study were knom1 to ha \·e been onr 30 years old 

when appointed to trnining, there is the possibility that relati Yely few of them were eYer 

among the top performers at any stage of their 

careers. "'bile the degree to which this may 

haYe actually occm-red cannot be ascertained 

from the data and information collected, some 

likelihood of snch uncontroliD ble bias in the selection of the sample must be noted. In other 

words, significant proportions of the differences 

between the mean leYels of job performance of 

the older and yonnger snbgronps may not ha ,-e 

been due to aging effects after enf1·y into the 

FAA bnt rather to pre-entry aging effects (such 

as deficits in learning ability, aptitudes, motivational factors, and the like) which might have 

precluded the older ATCSs from performing on 

a highly competitive basis with their younger 

counterparts throughont all career phases. 

The correlation between Entry Age and Age 

'Vhen Rated ''"as, as mentioned. .81. Had a 

perfect positive correlation (i.e., an r of 1.00) 

been obtained bebYeen the two, then Years of 

FAA ATC Experience would have been inYariable, or identical, for all subjects and thus 

would haYe precluded any relationship whatsoe,·er between experience and performance or 

between experience and either age variablebecause FAA ATC Experience was, for nll subjects except those ha,·ing breaks in rvice, 

simply the difference between their ages at entry 

and when rated. 

Howe,·er, the total sample yielded correlations 

of .63 between Age 'Vhen Rated and experience 

and .03 between the latter and Entry Age. 

)foreoyer, significant im·erse relationships Wb!C 

obtained between the criterion ya.riable (Overall 

RLG R Rating) and both age variables and also 

length of experience, with the lowest of the 

three r's, a - .29, pertaining to experience. 

Training Entry Age correlated -.35 with performance, whereas Age "'hen Rated, which had 

correlated .63 with experience, yielded a validity 

coefficient of - .44. Inasmuch as length of experience was generally the difference between 

Entry Age and Age 'Vhen Rated, logic would 

dictate that the coefficient of -.29 also reflects 

the relationship that would have been obtained 

between performance and Age " Then Rated if 

all subjects had been of the sarne Entry Age. 

17 

OornJJarison of Empirical R elationships by 

Facility. Returning to Table 8 for a ·11parison 

of the intercorrelations by facility, it should be 

noted that the r's between the two age vnriables 

ranged from .64 (for the Denver, or "DEN," 

subgron p) to .97 (for the ATCSs at the Norfolk, 

or '·ORF," Tower). As expected, most correlations between Experience and Entry Age were 

rather small and only one, n -.38 (pertaining 

to the Kansas City facility, designated as :MKC") 

proYed statistically significant (p<.05). In contrast, the coefficients reflecting the relationship 

of Experience to Age "Then Rated ranged from 
...... 

00 

Table 3 . 

Faci 1. 

and N 

ATCSs 

--

ATL 

49 

-

MIA 

58 

-

DCA 

51 

-

DTW 

40 

-

SAT 

29 

-

BOS 

42 

PHL 

38 

-

STL 

31 

-

DEN 

34 

Intercorrelations of job performance, age, and experience variables for ATCSs of each of 17 TAT

fa cilitie s . 

Variables & Intercorrelations Variables & Interco

1 2 3 4 1 2 3 

Trng, Age Years Overall Facil, Trng. 

Entry 

Age 

Age 

When 

Rated 

Years 

Var, Entry When FAA ATC RLGR and N Var, FAA A

# Mean S.D. Age Rated Experi, Rating ATCSs # Mean S,D, 

1 25.6 4.1 .72** -.06 -.16 CLE 1 25.1 3.1 .so** 

2 35.9 5. 2 .65"* -.39** 32 2 35.9 4.7 

3 10.4 3. 6 -. 39** 3 10 . 9 2. 9 

4 5.2 0.5 4 5.2 0.8 

1 25,6 4.0 .77._ .-13 -.28*- MSP 1 26.4 2.8 .75** 

2 36.4 5.9 • 73** - .38** 28 2 37.2 4.5 

3 10.9 3.8 -.29* 3 10.9 2.9 

4 5.1 0,6 4 5,2 0.6 

1 25.7 3.3 .so** -.o9 -.12 MKc 1 26.8 s.s .93** 

2 35.1 3 . 9 .52** .oo 33 2 37.2 7.3 

3 9.4 2.2 .17 3 ]().4 2.9 

4__ - 5 • 2 0 • 8 4 5 • 3 0 • 6 

1 25.2 2.9 . 78** .07 -.31* TPA 1 27.6 4.8 .65** 

2 3 5. 9 3. 8 • 6 7** - • 3 7* 3 2 2 3 7 . 2 5. 8 

3 10.7 2.4 -.24 3 9.5 4.6 

4 5.2 0.6 4 4.9 0.5 

1 25.6 3.4 .09 -.37* CMH 1 27,6 5.4 .87** 

2 3 6 . 0 4 . 6 • 6 7** - • 52** 31 2 3 7 • 7 6 . 8 

3 10.6 2.7 -.40* 3 10.1 3.4 

4 5.0 0.7 4 5.3 0.8 

Expe

.24 

.77

.15 

• 7

.38

.70

-.24 

.5

.1

.6

1 26.0 4 . 0 .83.,....,. .os -.59** 1 29--:1 6.6 -:97** .2

2 36.6 5.1 .61** -.55** 35 2 39.5 7.3 .4

3 10.6 2.9 -.14 3 10.4 1.7 

4 5.2 0,7 4 5.0 0.8 

1 26.9 5.5 -.40* MEM 1 25.2 2.8 .65** .1

2 38 • 2 7 • 2 . - • 28 2 3 5. 3 5. 0 • 8 

3 11.2 4.3 -.38* 3 10.0 3.8 

A 4__._a_ _ _Q__,_8 __ _ _ 4 5,5 0,6 

1 25.5 3.1 .82** -.05 -.32 IND 1 26,3 4.2 

2 35.0 3. 7 . 52** - .40* 22 2 36.9 5.1 

3 9. 5 2. 1 -. 26 3 10.6 2. 8 

4 5,2 0,6 4 5.2 0.7 

1 24..7 3.2 ,64** -.09 -.22 T<YrAL 1 26.1 4.3 

2 35.4 4.4 .7o** -.37* 613 2 36.5 5.5 

3 10. 8 3 • 3 - • 28 3 10. 4 3 • 2 

4 5.0 0.7 4 5.1 0 . 7 

.84** -.0

.5

.81** .0

.6

* Sta tis ti ca lly significant at the .05 le vel ; ** Statistically signi f i cant at the . 01 level. 
.47 to .82, all of \Yhich were significant at the .01 

le1·el of probability. 

Entry Age wns im·ersely related to the job 

ratings of personnel at e1·ery facility. These 

correlations ranged from -.12. for " 'ashington 

N"ational ("DCA") Airport, to - .5fl, for the 

Boston ("DOS~') fa cility, fi,-e of the 17 r's ''"ere 

significant at the .01 ]eye] and fom at the .05 

le,·el. The DC'A Tower was also unusual in that 

it was the only fa cility for which the _\.TCS 

rDtings failed to be im·ersely related to both 

Experience and Age " 'hen Rated. The correlation between the latter and the criterion nuiable 

for the remaining lG facilities ranged from -.37 

to - .66, nine of which \Yere significant at the 

.01 leYel and six at the .05 ]eye]. Aside from 

DCA, there \Yas only one facility (Boston) at 

which Age ·when Rated failed to be more in-

,·ersely related to performance than Entry Age. 

The lowest of the negati,-e correlations between 

Experience and the criterion Yariable \Yas -.14 

(for Boston) and the highest \Ya s - .52 (for the 

"C~1H," or Cohunbus, Ohio, facility) . Five of 

the latter were sig11ificant at the .01 le,·el and 

six at the .05 le1·el. For most fa cilities, howe,·er, 

it \Yas found that Experience was not as highly 

rein ted to performance as was Age \Yhen Rated; 

moreoYer, at nine facilities, Experience also 

pro,·ed less effectiYe . than Entry Age as a predictor of performance. 

Since se1·eral of the largest (negati1·e) correlations between_ performance and the hYo age 

variables and also between the criterion nrinble 

and Experience pertained to facilities which 

were among those ''"hich ranked rather lo''" with 

respect to IFR traffic 1·olume, each of the three 

sets of correlation coeffiC'ients \Yere rank ordered 

;mel the ranks were then correlated agDinst the 

IFR-traffic-volume ranks of the respecti ,-e facilities. Although not shown in any table, the 

resulting "rho" coefficientsG were - .2i for Entry 

Age, - .4 7 for Age \Vhen Rated, and - .-!!) for 

Experience. Only the correlation of - .-±fl was 

statistically significant (Jl < .05). Nevertheless, 

the latter two coefficients indicated that the inverse rein tionshi ps between performance and 

both Age \Vhen Rated and Experience \Yere indeed generally more pronounced at the facilities 

having relatively low IFH traffic loads. 

Oompm·ison of Resnlts joT Ili_qh-, Intermediate-, and Low-Ranked IFR Facilities. Table 4 

1!} 

and Figures 5 and 6 present the results of analyses in ''"hich the totDl sample was di1·ided into 

three subsamples. The subgroups w·ere established by categorizing the facilities in terms of 

IFR operations performed during the fiscal year 

(FY) 1D69. The first subsample~ designated as 

'·High IFR," consisted of 198 subjects who 

11·orked at the four fa cilities which had o\'er 

300,000 IFH operations each. The "Intermediate 

IFR Subsample" consisted of 206 who were stationed at nny of the six facilities luHing 01·er 

:200~000 but less than ~00,000 such operations, and 

the remaining ~09, referred to as the '·Lo\Y IFR 

~ubsample,~· represented all journeymen of the 

se1·en facilities "·hich handled lesser amounts of 

IFR traffic. (It should be emphasized that the 

three en tegories were est a blishecl for research 

pmposes only: the official classification of each 

of the 17 facilities \\·as "LeYel-III," the highest 

of three le1·els into which any TATC fa cility 

\YUS classified at the time the study was conducted.) 

Table -± sho\YS the intercorrelations of the two 

age ,-ariables, FAA .ATC Experience, and the 

criterion 1·ariable for the three subsnmples. Correlations between the two age Yariables ranged 

from .75 to .85, with the lowest being obtained 

for the High IFH Subsample and the highest 

relating to the subjects of the se1·en lo,Yestranked facilities. As expected, Experience was 

not appreciably related to Entry .Age for any 

snbsample~ whereas its correlation with Age 

" Then Rated "·as .59 for the Lo'" IFR Subsample 

and .67 for the other two. There \Yas no subsample for \Yhich performance failed to correlate 

more highly with Age \Yhen Rated than \Yith 

Entry Age or Experience. A fact of m·en 

greater importance was that the high es1 of the 

validities for each of the three nll'iables patained to the Low !Fl.' Subjer·ts and that the 

lowest pel'fained to tho8e of fh(' fottJ' hirJhestmnked f(L('ilities. The Yalidity coetli.cients of 

Entry Age for the High. Intermediate. ;nul LO\Y 

Snbsamples, respecti1·ely, \Yere -.:20, - .3fl. and 

- .-±6; correspomling correlations for Age \Yhen 

Hated were - .~7, -AS, and - .;>5, and those inYolving Experience were - .Hl, - .31, and -.;H. 

The Intermediate and the Low IFH Snbsample 

differed significantly (p< .05) from the High 

IFR Subsample with respect to the correlations 

behYeen performance and each age 1·arin ble. 

Other differences 11·ere not statistically signifi-
Table 4. Intercorrelations of performance, age, and experience for three ATCS 

subsamples: those of TATC facilities having annual IFR operations 

of over 300,000 each, those with 200,000 to 300,000, and those with 

less than 200,000 each . 

Var. 

Groups of TATC Facilities & N ATCSs # 

Four facilities having over 300,000 1 

Instrument Operations each during 2 

1968. (ATL, MIA, DCA & DTW) 3 

Grouped data for 198 ATCSs. 4 

Six facilities having 200,000 to 1 

300,000 Instrument Operations each 2 

during 1968. (SAT, BOS, PHL, STL, 3 

DEN & CLE) Data for 206 ATCSs. 4 

Seven facilities h~ving less than 1 

200,000 but over 100,000 Instru- 2 

ment Operations each during 1968. 3 

(MSP, MKC, TPA, CMH, ORF, MEM& 4 

IND) Grouped data for 209 ATCSs. 

Total: 17 facilities having 111.731 1 

to 374,354 Instrument Operations 2 

each during 1968. N ATCSs = 613 3 

4 

Mean 

25.5 

35.8 

10.3 

5.2 

25.7 

36.3 

10.6 

5.1 

27.1 

37.4 

10.3 

5.2 

26.1 

36.5 

10.4 

5.1 

S.D. 

3.6 

4.9 

3.2 

0.6 

3.9 

5.2 

3.2 

0.7 

5.0 

6.2 

3.2 

0.7 

4.3 

s.s 

3.2 

0.7 

Variables & 

1 2 

Trng. Age 

Entry When 

Age Rated 

• 7 5 

.80 

.85 

.81 

Intercorrelations 

3 

Yrs. of 

FAA ATC 

Experi. 

-.09 

.67 

.09 

.67 

.08 

.59 

.03 

.63 

4 

Overall 

RI.GR 

Rating 

-.20 

-.27 

-.19 

-.39 

-. 48 

-.31 

-.46 

-.55 

-.34 

-.35 

-.44 

-.29 

All co rrelation coef f icients ar~ statistically significant at the . 01 level excep t 

those of training entry age vers'us experience. 

cant. Nonetheless, the findings appeared to contradict. the rat her widespread belief _that the 

older and most experienced ATC!::is at the more 

complex faci liti es tended to ped01 n~ less well 

than their counterpa rts at relati,·ely low-ranked 

install ation ''· J lo 11·c,·er, the results of the correlatiuHal analysis were deemed insufficient to 

fully rf•soh·e snch an issue. 

Aclclit.ional ana lyses are presented in Figmes 5 

and G. The data for each of the three suhsamples 

were ann lyzed in much the Sllllie manner as 

pre1·iously sho\l'n in Figures ~ and ± for the 

total group of () ~ subjects. First. the RLGR 

means \\·ere colllputed and plotted by age le1·el 

fo r the "ubjects " ·ithin each subsample who had 

·'t2 or Jr,.> ... or" ):\ or mon'' years of F.AA ATC 

ex peri<.'JH t\ (Figure :1). Secondly, the rating 

20 

means were obtained for the A TCSs of differential experience ]e,·els represented within the 

dichotomized age groupings of "40 or younger" 

and "41 or older." 

Before considering other results stemming 

from these analyses, it should be noted that the 

subsamples. although roughly the same size, contained disproportionate numbers of the older 

and/ or more experienced subjects. Only 95 of 

the 613 ATCSs, it may be recalled, were over 

40 years of age. The tabular section of Figure 6 

shows the distribution of the 95 among the three 

snbsamples. Of the 95, only 19 (20 per cent) 

were in the High IFR Subsample, 29 (30.5 per 

cent) IYere on the ATCS staffs of installations 

we categorized as " Intermediate," and 47, representing ±9.5 per cent of the subgroup, '"orked at 
t-:J 

,..... 

Four Top-ranked IFR Facilities Six Intermediate-ranked IFR Faciliti es Seve n Lowest-ranked I

(ATL, MIA, DCA, & DTW) (SAT, BOS, PH L, STL, DEN, & CLE) (MSP , MKC, TPA, O lll, O

5.50 ' 

"" ' o--o .....-' • 12 years Overall 12 years ""' . 'I • ""' experience .............. exp. or less or less 0 12 5.00 I ·-· t 

I 

""' \\\

I 

I RI.GR I ·\ 13 years I experi. I 4. so or more I ' 0 ' 

' -- 13 yea r s ' 0 Rating 

cxpt·riC'nC{' 

0 Pr mprt· 

·,-. 

4.00 ' 

' 

0 

13 yea rs cxp . 

or more 

Chron. Age: 30 31- 36- 41- 46- .51· Group 30 31- 36- 41- 46- 51 Gr oup 30 31- 36- 41- 

& < 35 40 45 so & > Total & < 35 40 45 so & > Total & <' 35 40 45 

12 years N 10 97 68 5 4 1 185 11 98 68 7 5 2 191 12 85 63 16 

experience Mean 5.5 5. 2_ - 5.1 5.2 s.o s.o 5.2 5.2 5.3 s.o 4.8 4.1 4.1 5.1 s.s 5.4 5.3 5.1 

or less s.o,, .4 :6 .6 ,6 .3 ,6 .4 ,6 • 7 • 7 ,6 .7 .s .6 .s .6 

13 years N 4 1 3 5 13 6 4 5 15 2 9 

experience Mean 5.3 5.3 4,4 4.3 4. 7 4.4 4,2 3,9 4.2 5.1 4. 5 

or more S.D. ,8 • 7 .6 .8 .7 1.0 1.0 .8 • 5 

Combined N 10 97 72 6 7 6 198 11 98 68 13 9 7 206 12 85 65 25 

experience Mean s.s 5.2 5.2 5.2 4. 7 4.4 5,2 5.2 5.3 s.o 4.6 4.1 4.0 5.1 s.s 5.4 5, 3 4.9 

groups S,D, .4 .6 .6 .5 .6 ,6 .6 .4 .6 .7 • 7 .8 .8 .7 .s .6 . 5 .7 

' 

5. Means of Overall RLGR Ha tings by age levels for dichotomized experience groups of Terminal A'l'CSs working in Level- 

relatively high, intermediate, or low volumes of IFR traffic. 
to 

to 

5.50 

Overall 

5.00 

RI..GR 

4.50 

Rating 

4.00 

Years experience 

in FAA ATC work 

Age 40 N 

or younger Mean 

Age 41 

or older 

Combined 

age 

groups 

S.D. 

N 

Mean 

S,D. 

N 

Mean 

S.D. 

Four Top-ranked IFR Facilities 

(ATL, MIA, DCA, 6 DTW) 

age 40 

or younger 

--. 

. o --- I , 

\ 

I 

• 

I 

I 

I 

I age 41 

or older 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

• 

Six Intermediate-ranked IFR Facilities 

(SAT, BOS, PHL, STL, DEN, 6 CLE) 

• 

"'-... age 40 

"'-... or younger 

I 

·--· 

0 .... .; • 

I ........ • ,--' \ 

I age 41 \ 

I or older \ 

I \ 

I . \ 

I \ 

I \ 

I \ I 

I 

I 

I 

• 

Seven Lowest-ranked IFR 

(MSP, I«C, TPA, CMI!, OR

, age 40 

'--

............. , or young

./' ' 

. "' ' ' ' 

age 41 ' \ 

or older • 

""· 

' ' ' ' ' _ 

.... 

8 

6< 

9-

10 

11-

12 

13- 17- 21 Group I 8 

16 20 6 > Total 6 < 

9-

10 

11- 13- 17- 21 Group I 8 

12 16 20 6 > Total 6 < 

9- 11- 13-

10 12 16 

55 74 46 4 

5,1 5,2 5,3 5,3 

.7 .6 ,6 ,8 

1 

4.6 

6 3 

5.1 5,2 

,2 

2 7 

5,3 4, 2 

,4 

56 

5.1 

80 49 4 2 7 

5,2 5,3 5,3 5,3 4,2 

.7 • 5 ,6 .8 .4 

179 

5,2 

.6 

19 

4,8 

,6 

198 

5,2 

,6 

49 65 63 

5,3 5.1 5,1 

,6 .6 ,7 

1 

3,8 

50 

5,3 

,6 

4 9 

4,6 4.5 

.7 

69 72 

5,1 5,0 

• 7 ,7 

4 7 

4.6 3.9 

.9 1,0 

4 7 

4,6 3,9 

.9 1,0 

4 

4,2 

,1 

4 

4,2 

,1 

177 

5,2 

,6 

29 

4,3 

,8 

206 

5,1 

,7 

46 71 43 2 

5,4 5,4 5,3 5,1 

.6 .6 .5 

6 

4.9 

,6 

52 

5,3 

,6 

9 

5,1 

,8 

12 11 

4,6 4,2 

.6 ,6 

80 55 13 

5,4 5,2 4,3 

,6 ,6 .7 

FIGum; 6. Means of Overall RLGR Ratings by experience levels for dichotomized age groups of Terminal A'l'CSs working in Level-I

relatively high, intermediate, or low volumes of IFR traffic. 
facilities which had less than 200,000 IFR operations during FY -1969. A con.-entional t tests 

indicated that the Low JFR Snbsample included 

a significantly (p<.01) greater proportion of the 

95 older subjects than either of the other two 

snbsamples. Also, the resnlts of a Chi-square 

tests indicated that the proportions of the older 

and younger subjects in the three subsamples 

differed significantly (p<.01) from those expected on the basis of a random distribution. 

Althon:rh only 50 of the 613 snbjects possessed 

FAA A TC experience of 1~ years or more, 22 of 

them ( 44 per cent) were represented in the Low 

IFR Subsample, 15 ( 30 per cent) were stationed 

at "Intermediate" facilities, and only 13 (26 per 

cent) controlled traffic at any of the four topranked IFR installations. However, no statistically significant differences were found with 

regard to the distribntion of the differentially 

experienced subjects among the three snbsamples. 

Quest jo1· ExplanationB Why Few Olde?' 

ATCSs Worked Within High est-Ranlced Facilities. The authors consulted a number of ATCoriented personnel whom they felt might be able 

to offer plausible explanations as to why the 

older and/ or more experienced subjects were not 

proportionately distributed among the High, 

Intermediate, and Low Subsamples. The most 

cogent explanations were based on the common 

assumption that the complexity or difficulty of 

ATC work varied from facility to facility in 

accordance with the types and amounts of air 

traffic which they handled. A frequently advanced theory held that the resiliency of ATCSs 

to work-related stress effects generally declined 

with aging, which was a concomitant of experience and that, as a consequence, the screening 

effects (i.e., attrition rates) had probably been 

greatest (particularly with regard to the oldest 

ATCSs) at the busiest IFR facilities and progressively lower at the intermediate-ranked and 

lowest Level-III facilities. Se,·eral such proponents, and others with different viewpoints, 

speculated that many of the older and more experienced A TCSs within the lower-ranked facilities in 1969 may have represented transfers, 

,-olitional or management-induced, from higherranked Level-III Terminal facilities or from 

other types of facilities wherein they experienced 

difficulty in performing ·at a fully satisfactory 

level. It was also opined that many of the currently older and/ or more experienced ATCSs 

may always have been relatively mediocre performers, or otherwise they probably would have 

been promoted to positions of supervisory status 

(by 1969). 

A. Tmining-Entry Age. The frequency with 

which the conferees alluded to training-entry 

age and its presumed implications prompted a 

comparative analysis of the subsamples with regard to the entry ages of those subjects aged 41 

and older at the time the rating data were collected. In examining the frequency distributions 

(which are not shown in this report), the entry 

age of 36 was recognized as the best point on the 

distributions for purposes of discrimination. 

Only 26.3 per cent ( N = 5) of the 19 oldest subjects of the High IFR Subsample and just 24.1 

per cent (N =7) of the 29 ATCSs of age 41 and 

older at the six intermediate-ranked facilities 

were o,·er 35 years of age when they began their 

FAA A TC careers. In contrast, slightly over 

40 per cent ( N = 19) of the 47 oldest subjects of 

the Low IFR Subsample had entry ages of 36 

and higher. None of the differences, however, 

were statistically significant. Moreover, had the 

proportion for the low Subsample been of even 

greater magnitude, it would not necessarily have 

lent support to the claim that subjects who entered the ATC system relatively late in life 

tended to experience less difficulty in surviving 

the screening hurdles at the low-ranked facilities 

than at intermediate or high-ranked IFR installations. (No data or information were available 

with which to resolve the issue.) 

23 

B. Facility Tmnsje1·s. Some insight regarding the matter of transfers was obtained by 

examining the controllers' responses to certain 

items of the Personal Data and Background 

Form. The vast majority of the older and more 

experienced ATCSs within facilities of each of 

the three categories was found to have been in-

,·olved in at least one transfer and more than 

half of them indicated that they had previously 

worked at two or more ATC installations. Howe,·er, all differences between the three subgroups 

\Yith respect to percentages involved in one, two, 

or three or more transfers were not statistically 

significant. It was also determined that the 

transfers of some subjects within each subsample 

had occmred fh·e to twenty years earlier than 

those of others and that the facilities from which 
t.hey transferred included Air Route Traffic 

Control Centers and V FR Towers, as well as 

TATC IFR facilities of dilTercnt levels. Thrse 

findings nnd the difficulties whi ch would have 

arisen in comparing all the facilities in terms of 

amounts and types of traffic handled during 

various years Jed to cancellation of plans for 

analyses bearing upon the hypothesis that "most 

transfers of the older and more experienced 

controllers were from jobs of '.qreater complexity' 

to those of 'les/ier complexity'." 

C. Mean Ratings by Age Le1·el for the 1'h1·ee 

Subsamples. A point which warrants re-emphasis is that the vast majority of the A'l'C-oriented 

consultants postulated that the difficulty of ATC 

work varied from facility to facility in accordance with IFR operations. HO\rever, the annlyses depicted in Figures 5 and G yielded no 

significant differences between the mean RLG R 

performance ratings of the three subsamples. 

The means were: 5.2 for the 209 ATCSs (of all 

age and experience groupings) of the se\·en 

lowest-ranked facilities, 5.1 for the 206 representing the -combined staffs of those we categorized as intermediate, nnd 5.2 for the 198 who 

handled the heaviest annual IFR traffic loads. 

Analyses in which the age and experience \·ariables were dichotomized also yielded findings 

which were highly consistent across the three 

subsamples. In each subsample, the mean RLGR 

performnnce rating of those subjects having 1~ 

or more years of FAA ATC experience was 

found to be significantly lowe1· (p< .01) than 

that of the lesser experienced subjects. Also, 

there was no subsample for which the mean rating of subjects aged "41 nnd older'' failed to be 

significantly lowe?' than that established for the 

subjects "40 and younger." 

However, the detailed anulyses in which the 

rating means were obtained for subjects within 

each of several age brackets and experience le\·els 

indicated that the relationships of both age and 

experience to performance were rather markedly 

different for the High Yersus the Intermediate 

nnd Low Snbsamples. This is illustrated by the 

fact that the most unique of the three graphs 

shown in Figure 5 and the most unique of those 

presented in Figme () pertained to the 198 

ATCSs of the four highest-ranked of the 17 

IFR facilities sun-eyed. 

24 

Some 18!3 of the 19Fl subjects of the High IFR 

Suhsample possessed no more than 12 years FAA 

ATC experience. Ten of the 1H5 were less than 

:n years old. As sho\m in Figure 5, these ten 

received a mean performance rating of 5.5, which 

was only slightly higher than the· rating means 

(of !'>.2, 5.1, !'>.2, !J.O, and ;;.O) of their comparably 

experienced colleagues of the age brackets 31-3!'>, 

!3G-40, 41-4:i, 4G-!JO, and fil anJ older. :\!oreover, 

the five youngest (i.e., fom of age :l6-40 and one 

of age 41) of the 13 subjects in the Iligh IFR 

Subsample who had 1 ~ years experience or more 

also received commendably high rutings, whereas 

the only means which were relatively low pertained to three of the most experienced subjects 

of the age bracket 46-:iO and five who were !'> 1 

or older. 

Unlike those depicted for the High IFR Subsample, the plotted means (shown in Figure 5) 

for the Intermediate ai1d Low IFR Subsamples 

reflected successi 1·ely lower performance levels 

for the subjects of erery age bracket beyond 

~1-:15, irrespecti 1·e of experience; and the greatest of the differences between subjects of adjacent age brackets im·oh·ed those 41-45 and those 

46-50. The Intermediate Subsample included 

15 subjects with 1:1 years or more FAA ATC 

experience; the six youngest of the 15, in the 

41-45 age bracket, recei\·ed a mean rating of 

4.4 which was appreciably below that of their 

lesser experienced colleagues of the same age 

brncket but slightly higher than that of their 

four comparably experienced coworkers of age 

46-50 and considerably better than the mean 

rating of the fi\·e oldest of the 15 most experienced subjects. For the Low IFR Subsample, 

the plotted mean ratings of the 22 ATCSs who 

had 13 years experience or more tended to parallel those of the 187 less experienced controllers; 

most differences between the means of the differentially experienced subgroups of the various age 

brnckets were rather small and, more importantly, there was no age intenal in which the 

subjects of the upper experience category recei\·ed a higher mean rating than their coworkers 

of the lower experience category. 

Although not shown, the correlations between 

age and performance were obtained for the experience subgroups of the separate and combined 

subsamples. Correlntions between the two variables for subjects of the lower experience category were - .13, - .35, and -.36 for the High, 
Intermediate, and Low Subsamples, respectively, 

and -.28 for the combined subsamples. Corresponding correlations for the ATCSs having 13 

years expenence or more were - .68, -.51, and 

- .61, with the cumbined subsamples yielding a 

correlation of -.58. 

Figure 6 presents a comparative analysis of 

the three subsamples with respect to the performance means of the subjects aged "40 or 

younger" and "41 or older" within each of six 

length -of -experience subgrou pings (i.e., "8 years 

or less," "9-10," "11-12," "13-16," "17-20," and 

"21 years or more"). Looking first at the plotted 

means of the y01mger subjects only, it should be 

noted that all differences between the experience 

subgroups, within and between the three subsamples, are reb tively minor and, though there 

is little similarity between the patterns of the 

plotted means, the results for each of the subsamples indicate no more than a negligible relationship between their ratings and experience. 

The rating means shown in Figure 6 for the 

ATCSs of age 41 and older of the high-, intermediate-, and low-ranked installations reflect a 

high degree of variability, with most of the lower 

means pertaining to those having the greater 

amounts of experience. The means for all but 

eight of the 198 ATCSs who worked at the four 

busiest IFR facilities were, as mentioned earlier, 

commendably high; the mean rating for seven 

of the eight, all of whom were o\·er 40 years old, 

was 4.2, which was significantly lo"·er (probabilities ranged· from .01 to .05) than the mean 

ratings of both the younger and older ATCSs 

of most other experience leYels. In comparing 

the means by experience level for the 29. older 

subjects of the Intermediate Subsample, two of 

the three lowest means were found to pertain to 

subgroups having o\·er 16 years experience. Of 

the 47 older subjects in the Low IFR Subsample, 

six with experience of eight yenrs or less recei\·ed evaluations averaging -!.9 and nine with 

ATC service of 9-10 years receiYed a mean rating of 5.1, whereas those lun-ing progressi \-ely 

greater amounts of experience were generally 

rated much lower. )lore importantly. thel'e wa.~ 

no subsample in which the subjects of age 41 and 

older of any experience le·cel ?'eceiL·ed a mean 

mting greate1' them that of the youn,c;er (comparably experienced) subjects. The older subjects within some of the experience subgroups 

of the High IFR Subsample received mean rat25 

ings which were only slightly lower than those 

of their younger coworkers. Most remaining 

differences, howeYer, were of appreciable magnitude and some were statistically significant although at least one of the two means in each 

instance was based on a very small number of 

cases. 

Correlations (not shown) between the ungrouped experience data and performance ratings of the subjects aged 41 and older were 

-.62, -.15, and -.40 for the High, Intermediate, 

and Low Subsamples, respectively, and -.34 for 

those of the combined subsamples. Corresponding coefficients for the younger subjects were 

.07, -.07, and - .04 for the High, Intermediate, 

and Low Subsamples, and .00 (zero) for those 

of the combined subsamples. The experience 

and performance variables were not expected to 

be highly related for the younger subjects because few of them were of sufficient age to have 

permitted the n ttainment of lengthy experience. 

Even with such restriction-of-range effects, however, correlations much greater than those actually obtained would have been theoretically 

possible. 

Findings fo1' Combined Intermediate and Low 

Sttbsamples Only. In the last series of analyses 

undertaken in the study, intercorrelations were 

obtained bebveen age, experience, and performance for the combined Intermediate and Low 

Subsamples only. The correlation between age 

and performance was - .34 for the 378 subjects 

wh·o had 12 years experience or less, -.54 for the 

37 with 13 years or more, and -.50 for the 

merged experience subgroups. The r's for experience \·ersus performance were - .03, - .32, 

and - .33, respedively, for the 339 subjects of 

nge 40 and younger, the 76 of age 41 and older, 

and the 415 of all ages. A coefficient of .62 reflected the relationship of experience to age for 

the total group (of all subjects of the Intermediate and Low Subsamples). 

A regression analysis, in which the variance 

common to both the age and experience variables 

was determined, reYenled that Experience (for 

which a validity coefficient of - .33 had been 

obtained for the combined Intermediate and Low 

Subsamples) would have correlated -.03 with 

performance had the -!15 subjects been of identical age. Howe\·er, after extraction of the variance associnted with Experience, the age variable 
(which had correlated -.50 with performance) 

was found to have a residual validity of -.39: 

In other words, the correlation between Age and 

performance would have been - .39 had there 

been no variability in the experience of the 415 

subjects of the two subsamples. 

Although relatively few of the older ATCSs 

controlled trnffic at the four busiest IFR facilities, the results depicted in Figures 5 and 6, 

supplemented by those obtained in the correlational analyses, suggest that the prof-iciency of 

ATCS personnel at TATC IFR facilities is generally more apt to decline as a result of unknown 

factors associated with aging than as a consequence of presumed effects stemming from 

lengthy experience. 

IV. Summary and Conc1usions. 

Several findings emerging from this study of 

613 journeyman-le,·el ATCSs of 17 Le,·el-III 

TATC facilities wer~ remarkably like those obtained in a previous and highly similar study1 

of over 500 journeymen controllers of four Air 

Route Traffic Control Centers. Both investigations revealed that the mnjority of the controllers 

were under 36 years of age and/ or possessed 

FAA ATC experience of less than 11 years at 

the time their experimental ratings of job performance were collected. Notwithstanding such 

restriction-of-range effects, however, both studies 

provided convincing evidence of inverse relationships between the chronological ages and job 

performance evahw tions of A TCS personnel. 

Although an im·erse relationship was also obtained in each study between performance and 

length of ATCS experience, the predictive potential of the latter was not nearly as great as 

that of age, nnd its influence was virtually nil 

after extraction of the variance associated with 

age. 

In the ARTCC study, as in the present investigation, an examination of the rating means 

by age grouping indicated that the highest of 

the averages pertained to the ATCSs of age 30 

and younger whereas the means for controllers 

of age 31-35 and of each succeeding five-year age 

bracket were progressively lower, with the greatest decrements pertaining to those of the age 

subgroups 36-40, 41-45, and 46 and older. A 

comparati,·e analysis of the ·rating menns by 

experience level for the ARTCC specialists re26 

vealed negligible differences only betwoon all 

subgroups having six to ten years experience, 

whereas the ayerage rating for the most experienced subgroup, comprised of only 18 subjects 

having 11 years service or more, was lower, yet 

not appreciably lower, thnn that of each of the 

lesser experienced subgroups. Inasmuch as the 

experience of the TATC subjects covered a 

greater range than that represented by the 

ARTCC sample, the results stemming from the 

corresponding analysis of the T ATC data should 

be considered more meaningful and reliable than 

the former. The results reflected a high degree 

of comparability between the perft>rmance levels 

of the TATC subgroups having 5-6, 7-8, or 9-10 

years experience and also between each of the 

latter and the subgroup with 11-12 years service; 

howe,·er, the respecti,·e means of those having 

13-16, 17-20, and 21 or more years experience 

were contrastingly lower and each differed significantly (at either the .05 or .01 level) from 

those obtained for lesser experienced subgroups. 

Only 12.5 per cent ( N = 66) of the 526 ARTCC 

specialists were over 40 yenrs old at the time 

their rating data were collected in 1965, less than 

4 per cent (N=21) of the 526 had more than 

10 years experience, and 15 of the 21 were among 

the (i(i who were 41 years of age or older. Ninetyfi ,-e of the 613 TA TC subjects, or 15.5 per cent, 

were 41 or older when rated in late 1968 or early 

1969; almost 37 per cent (N =226) had at least 

11 yen rs FAA ATC experience, 50 of the 613, or 

8.2 per cent, had 13 years or more, and 44 of the 

latter 50 were also among the 95 who were over 

40 years old. Assuming that the samples were 

at least somewhat representative of the FAA's 

ATCS population, these data suggest that, even 

at this time ( 1973), only a small minority of the 

controllers within the entire Air Traffic Management System are over 40 years of age and/or 

possess experience of more than 12 years. This 

does not, howeYer, relegate to unimportance the 

findings relating to such older and more experienced personnel. 

The Pearson product-moment ·correlations obtained in the present study between performance 

and both age and experience for the total sample 

of 613 TATC subjects should be regarded, like 

those reported in the ARTCC study, as being 

grossly attenuated. In other words, they probably represent gross underestimates of the in-
verse relationships that would have been obtained 

had the frequency distributions of nge and experience not been so positively skewed. 

One of the prime objectives of the TATC and 

ARTCC studies was an assessment of the interaction effects of age and experience upon performance. Unfortunately, abnormalities in the 

frequency distributions of both age and experience precluded application of many of the more 

sophisticated and normnlly appropriate statistical techniques, such as bvo-way analyses of ,-ariance and other treatments. Although relatively 

simple procedures were necessarily selected for 

the purpose, the results obtained in each study 

clearly illustrated that the interaction effects of 

age and experience were restricted to those subjects of age 41 and older. 

In both the TATC and the ARTCC studies, 

an analysis of the performance rating means of 

the subjects aged "40 and younger" versus those 

"41 and older" within each of several length-ofexperience groupings indicated that: (1) the 

younger subjects of every experience le,·el tended 

to receive higher performance evaluations than 

those over 40 years of age, (2) the greater mean 

differences, most of which were statistically significant in the TATC study, pertained to the 

differentially aged subgroups having over 10 

years experience, and ( 3) the means of the 

ATCSs of age 40 and younger fl t all experience 

levels were remarkably similar-with the ratings 

of the most highly experienced subgroup (of 

younger ATCSs) averaging slightly hi,qhe1· than 

those of the lesser experienced subgroups. ~[oreover, the results of corresponding analyses in 

which the experience variable was dichotomized 

failed to support the widespread belief that 

length of experience, when onsidered independently of aging effects, tends to adversely 

affect ATC job performance. Both studies, however, have convincingly demonstrated that controllers over 40 years of age are generally rated 

as less proficient at their jobs than their younger 

colleagues and the findings, although not deri,·ed 

through follow-up-study procedures, also suggest 

that the presumed aging effects tend to become 

progressively more pronounced for those mei1 

over 40 as they lengthen their ATCS tenure 

beyond 10 years. 

A great deal of additional research would be 

required in order to determine reliably the rea27 

sons why the older controllers generally received 

the lower mean ratings. However, we are not 

inclined to ascribe their lower mean ratings to 

the effects of physiological aging only. One 

possible explanation is that the chronologically 

older ATCSs may not have been as highly motivated to excel in their work as were their younger 

coworkers. Other researchers and ATC personnel with whom we have discussed both the TATC 

and ARTCC studies have pointed out that each 

study illustrated that the controllers over 40 

years of age at the time the rating data were 

collected were generally more experienced than 

the younger and, this being so, haTe postulated 

that many of the older controllers may never 

have been among the top performers at any stage 

of their ATCS careers-because otherwise they 

might already have attained promotions to positions beyond that of journeyman controller. 

Among the numerous additional theories, the one 

most frequently advanced held that the ratings 

may have been biased by the attitudes of the 

raters regarding age. Although neither study 

afforded an opportunity to reliably assess bias 

effects, it should be mentioned that practicnlly 

no correspondence was found in the TATC study 

between the ages of the raters and the ratings 

they rendered on controllers of various age 

levels. 

It should also be emphasized that the findings 

obtained in the present study, like those of the 

ARTCC study, were based on experimentally 

deri,·ed ratings of job performance which were 

collected at an nrbitrarily chosen point in time 

for controllers \vho represented only a small portion of the journeyman radar ATCSs of the 

entire ATM system. Neither study provided 

evidence regarding the true reliability of the 

ratings which 'vere collected for research purposes only. In terms of the official and periodic 

proficiency enlluations, all controllers had been 

considered satisfactory; had they been officially 

adjudged deficient in any respect, they would 

not have been permitted to engage in air traffic 

operations. 

'Whereas personnel of only four Centers were 

im·oh·ed in the ARTCC study, the present in-

,·estigation pertained to the. ATCS staffs of 17 

TATC facilities. Each of the 17, at the time the 

suney was conducted, wns officially elassified by 

the FAA as a Level-III Facility, indicating an-
nual IFR operations of at least 100,000. However, such opemtions ranged from Ill ,7:11 at one 

facility to more than :fl4,000 at another. The 

results of :111 analysis indieated that the relationships of age and experience to performance 

tended to vary from facility to facility in acconlance with IFR traffic volumes. 

Additional analyses were therefore undertaken 

in which the subjects were grouped to establish 

three subsamples. The first·, designated (for .research purposes only) as the "High IFR Subsample," consisted of 1fiR snbjects who worked 

at facilities having over :300,000 IFR operations 

each; 206 who controlled trnffic at. any of the six 

facilities having o1·er 200,000 hut less than 

000,000 such operations comprised the "Intermediate Subsample"; anrl the remaining 20!), of 

the se1·en facilities having lesser amounts of TFR 

traffic, were designated us the "Low IFR Subsample." Although approximately equal in size, 

the samples contained disproportionate numbers 

of the older and more experienced subjects. Of 

95 who were over 40 years old, 4f.l.fi per cent 

were m the Low IFR Snhsample, :\O.fi per cent 

were m the Intermediate, and only 20 per cent 

were in the High IFR Suooample. Of the 50 

who possessed FAA ATC experience of 1:3 years 

or more, 44 per cent were on the ATCS staffs of 

the se1·en lowest-ranked IFR facilities, 00 per 

cent worked at those designated as Intermediate, 

and only 26 per cent held positions at the busiest 

IFH installations. 

The reasons why the older and more experienced subjects were not proportionately distributed among the High, Intermediate, and Low 

Subsamples are unknown. The finding, however, 

does not necessarily warrant the presumption 

28 

that the difficulty of control work was so much 

greater in the l•igher-rankcd facilities as to result in differentially higher screenout rates (i.e., 

attrition rates) of the older ancl more experienced personnel. To the contrary, it is possible, 

though perhaps not likely, th;Lt higher percentages of the men who qualified for appointment 

to FAA ATCS positions at relatively advanced 

ages were selectively assigned to the low-IFRtraffic-density facilities. Hegardless of the reasons, the disproportionate distribution of the !)f.i 

older controllers among the three subsamples 

was considered one of the most intriguing of the 

findings obtained in the study. 

In none of the subsamples did the mean performance rating of the subjects aged 41 and 

older of any experience level exceed the me:~.n 

rating of the younger (and comparably experienced) subjects. H was also ascertained that the 

inverse relationships of age and experience to 

the performance 1·ariable were much more pronounced for the Low and Intermediate Subsamples than for the High IFR Subsample. 

However, the results of regression analyses on 

the data of each of the thrE:e subsamples indicated that ( 1) when the variance of age was 

theoretically nullified, or held constant, experience would correlate negligibly with performance, and (2) had the subjects possessed identical 

amounts of experience, their ratings would still 

have correlated negatively, and significantly so, 

with their ages. Such findings suggest that 

TATC ATCS performance is generally more apt 

to decline as a result of factors associated with 

aging than as a consequence of presumed effects 

stemming from lengthy ATC experience. This 

is essentially the same conclusion previously 

reported for ARTCC personneJ.l 
REFERENCES 

1. Cobb, B. B. : The Relationships Between Chronological Age, Length of Experience, and Job Performance Ratings of Air Route Traffic Control Specialists. 

FAA Office of Aviation Meditine Report No. AM67-1, 1967. 

2. Cobb, B. B., C. D. Lay, and N. M. Bourdet: The 

Relationship Between Chronological Age and Aptitude Test Measures of Advanced-Level Air Traffic 

Control Trainees. FAA Office of Aviation Medicine 

Report No. AM- 71-36, 1971. 

3. Cobb, B. B., and J. J . l\Iuthews: A Proposed New 

Test for Aptitude Screening of Air Traffic Controller 

Applicants. FAA Office of Aviation ~Iedicine Report 

No. AM-72-18, 1972. 

4. Cobb, B. B., J. J . Mathews, and C. D. Lay: A Comparative Study of Female and )!ale Air Traffic 

Controller Trainees. FAA Office of Aviation l\Iedicine Report l'\o. A~I-72-22, 1972. 

5. Glaser, R. (Ed.) : Training R esearch and Educa.tion, 

Pittsburgh, l'niversity of Pittsburgh Press, 1962. 

6. McNemar, Q.: Psychological Statistics, New York, 

John Wiley and Sons, 1962. 

7. ~lin(>r, J . B.: l'ersou11cl and Industrial R elations: A 

Managerial Approach, New York, The )lacmillan 

Company, 1969. 

8. Smith, R. C., B. B. Cobb, and W. E. Collins: Attitudes and )!otivational Factors in Terminal Area 

Traffic Control Work. l<'AA Office of Aviation ~fedicine Report No. Al\I-71-30, 1971. 

9. Tiffin, J ., and E. J. McCormick: Iudustrial Psychology, Englewood Cliffs, Npw Jersey, Prentice-Hall, 

Inc., 1958. 

29 

10. Trites, D. K. : Problems in Air Traffic Management: 

I. Longitudinal Prediction of Effectiveness of Air 

Traffic Con trollers. FAA Civil Aeromedical Research 

Institute Report No. 61-1, 1961. 

11. Trites, D. K. : Problems in Air Traffic Management: 

VI. Interaction of Training-Entry Age With Intellectual and Personality Characteristics of Air 

Traffic Control Specialists. FAA Civil Aeromedical 

Research Institute Report No. 65-21, 1965. 

12. Trites, D. K., and B. B. Cobb: Problems in Air 

Traffic Management: III. Implications of Age for 

Training and Job Performance of Air Traffic Controllers. FAA Civil Aeromedical Research Institute 

Report No. 62-3, 1962. 

13. Trites, D. K., and B. B. Cobb: Problems in Air 

Traffic Management: IV. Comparisons of PreEmployment, Job-Related Experience With Aptitude 

Tests as Predictors of Training and Job Performance of Air Traffic Control Specialists. FAA Civil 

Aeromedical Research Institute Report No. 63-31, 

1963. 

14. Trites, D. K., and B. B. Cobb: CARl Research on 

Air Traffic Control Specialists: Age, Aptitude, and 

Experience as Predictors of Performance. FAA 

Civil Aeromedical Research Institute, Unnumbered 

Report, 1964. 

15. Whisler, T. L., and S. 1:<'. Harper (Eds.): Performance Appmisal, Research, and Pmctice, New York, 

Holt, Rinehart, and Winston, 1962. 

Appendix 1. Eva luati on form from which the Radar ( R), Local (L), Gene ral (G), Relative 

Proficiency (R), and Ove r a ll Ratings were derived . 

ATCS PERFORMANCE EVALUATION FORM 

Name of ATCS being rat ed Facility 

In evaluating the subject empl oyee , try t o consider his performance during the busier 

peri ods as much as possib le. Please try t o be r ea listi c in making your ratings. Everyone 

can't be average or excellent in eve r y thing. 

RADAR CONTROL LOCAL CONTROL 

~ 

"0 

0 

i:' 0 

00 ·~ ~ "6 ~ 

"0 c: c "' 0 <ll 

"' .... '-' 00 

"' .... .. "' <ll c .... ~ u <ll 

" " <ll > 0 "' > < 

"' 00 

.... "' "' "' ~ 

> .... < "' c "' " 0' :> ·..< <ll 0 00 "0 .... .... "' "' 2 c: 

"' ..... 

~. rate the c ontroller on each e l ement o f items 

1 through 7 with r es pect t o Radar Contr o l. 

Second, rate him on the same items with respect to 

Loca 1 Control. 

Next , rate the ATCS on the elements of General perf ormance and also render an Ove rall r ating . 

1. K:-10\o/LEDGE 

Knowledge o f pr ocedures and equipment 

2. COMPREHENSION 

(a) Distinguishing between r outine and 

potentially dange r ous situations 

(b) Ge tting and holding the picture 

3. JUDGMENT 

Making wise, appropriate deci sions (vs. r ash or 

nonappropriate) 

4. COMMUN ICATIONS 

~-~~~~~~--1-~---(a) Use of standard phrase ol ogy 

~f--r~~~~--~f----(b) Delivery technique 

(c) Clarity and understandability 

~t--r~~~~--~t----(d) Quantity (too much ? t oo little ?) 

5. TRAFFIC MANAGEMENT TECHNIQUES 

"' c: 

·~ ~"0 

"0 c: 0 c "' 0 

"' .... '-' ~ .... ~ "' u "' c 

6 " "' "" > 

~ 

"0 

0 

c 

00 

~ 

"' "' .., 

.... 

> "' 

< 

"' cG 

"' .... 

> "'

< 

:> 

0 

.... 

"' "' 

~ 

.... "' 

.S ~ .... "'"" .., 2 ..s 

~+-+-~~~+-+-+----(a) Timing -----------~~--------------------------1--r-t~~~-r-t-1 1-~~~~~~-r-~---(b) Capacit y to move traffic 

~f--r~~~~-~f----(c) Command of situati ons 

1-~~~~~~--r-~---(d) Prevention of delays thru good control techniques 

1-~~~~~~-r-~---(e) Planning provides sufficient safety ( ve r sus 

l ast minute corrections) 

6. PERFORMA.'lCE UNDER SIRE SS 

~t--r~~~~-~f----(a) Recognizing all aspects of a traffic situation 

1-~~~~~~--r-~---(b) Se lf confident but aware o f his limitati ons 

~t--r~~~~--~f----(c) Ability t o remain calm ~-----------------------------+~~+-~~K-~-+_, ~t-i-~--~1--T-t--(d) Ability t o remain tactful 

(e) Consistency in sa fe se pa r ation 

7. COORDINATION 

(a) Accomplishes at the pr op e r time 1-~~~~~~--r-~----(b) Overall effectiveness (und rstan~d-a b~l----c---mp~l~e-t-e~)~--~~t-1--Hr-~-t~~l 

8. GENERAL RELATED ELEMENTS OF ATCS PERFORMA.'lCE GENE RAL CONTROL 

(a) Ability to work effecti vely with othe rs 

(b) Willingness to assume his share in teamwork 

(c) Acceptanc e of suggesti ons and criticism 

(d) Tactfulness in making appropriate suggest i ons to others 

(e) Interest and pride in work 

(f) Efforts toward self improvement 

(g) Steady attention to work and c onduct 

(h) Adaptab~lity to changes in polici es, pr ocedure s, etc. 

(i) During periods of peak traffic or adverse wea ther, to 

what extent is this controller capable <>f meeting the 

demands of the "hottest" position(s) ? 

9. OVERALL RELATIVE RATING Use the sca le be l ow to rate the ove r al l proficiency of this controller relative l£ ~ the controllers ~ have known. (Indicate 

your rating by placing a check mark in the appr opriate box.) 

Upper Upper Lower Lower 

Top Intermediate Middle Middle Middl e Int ermediate Bottom 

10% 1 5'/, 157. 207. 15'/, 15% 10% 

--- -- --- -- -- -- --

1007. 907. 75% 60% 40% 257. 10% O% 

31 
to 

Appendix 2. Means of RLGR Ratings rendered by Supervisors of three aae aroups on ATCSs of various aa

Raters 46-50 

--· ' Supervisory 

... ' 

...... . ' 

......... 

5.00 - Raters51&> •---- ---• 

' . ', . ' Rl.GR - " ' ' ' \ 

' 

4.50 -

Rating \ Raters 

4.00 - 45 & < ,, ' . 

• 

Jl 

& < 36-40 41-45 46 & > 

Ratings Rendered on ATCSs of Different Age Groups 

Supervisory N Mean S.D. N Mean S.D. N Mean S.D. N Mean S.D. 

Raters N 

Age 51 & > 14 76 5.34 .81 39 5.03 .79 10 5.04 .71 12 3.93 1.16 Age 46-50 17 68 5.34 .86 53 5.39 .77 15 4.87 .91 18 4.00 .96 Age 45 & < 10 36 5.28 .96 31 5.12 1.06 15 4.96 .88 8 3.68 .88 

Total Saq>le* 41 180 5.33 .86 123 5.21 .87 40 4.95 .84 38 3.91 1.02 

*The data pertain to the RLGR Ratings obtained at several facilities from 41 Supervisors who def

ity privilege. The means of the ratings rendered by Supervisors of each of the age categories on ATC

youngest subgroups were significantly higher than their mean evaluations of ATCSs over 45 yea

they made no significant differentiation between any of the three younger groups. Within each of the 

none of the differences between the rating means proved statistically significant. 
<:>:> 

<:>:> 

Appendix 3. Means of RLGR Ratings rendered by Crew Chiefs of three age groups on ATCSs of various a

5.50 

0 

-

--

-

--

-

•== - Crew Chief -- . ,( Raters 

o' 

46 & > 

-

- 

-

s.oo 

-·-

0 

' ... ' ' ... .... RLGR ' ... .... ' ... ... ... ' Raters ... ... ' ... 4.50 - 41-45 ' 0 

• 

-

-

---

. 

Ratings 

Raters 

4.00 - 40 & < 

" 

35 6. < 36-40 41-45 46 6. > 

Ratings Rendered on ATCSs of Different Age Groups 

jcrev Chief N Mean S.D. N Mean s.D. N Mean S.D. N Mean S.D. 

Raters N 

Age 46 6. > 39 145 5.44 .88 95 5.22 .88 21 5.00 .70 31 4.49 .98 Age 41-45 14 42 .5.28 .89 33 5.28 .79 8 4.48 .79 8 4.34 1.14 

Age 40 6. < 20 79 5.29 .94 60 5.26 .85 14 4.42 1.06 9 3.78 .88 

rt'otal Sa'q)le* 73 266 5.37 .90 188 5.24 .85 43 4.71 .87 48 4.33 1.01 

*The data pertain to ratings obtained at several facilities from 73 Crew Chiefs who deferred the 

ilege. . The mean of ratings rendered on ATCSs of the oldest group by Crew Chiefs of·age 46 and older 

cantly lower than those rendered by the same group on controllers of either age 35 and young

significant differences in the means of ratings received by the four controller age groups were found 

age 41-45. The Crew Chiefs of age 40 and younger rated the oldest group and those 46-50 significantl

than either of the two younger groups . Within the ratee age groups, no significant differences were 

the mean ratings rendered by the three groups of Crew Chiefs. 
.;,:> 

>!'>-

Appendix 4. Means of RLGR Ratings rendered by ATCSs three age groups on ATCS peers of various ag

Raters 35 & < 

;;;> 

If - • -

, 

5.00 - ........ , ''' ......... _.. , 

• Coworker , , ' .... , ... ... Raters 36-45 ., ... 

., ' .... 

, • 

, ' ' , , .... • ' .... .... 4.50 - Raters 46 & > ' .... .... RI..GR 

.......... 

.... 

.... 

.......... 

.... 

.... 

.......... ' ... 

............ • 

4.00 -

Rating· • 

. 

35 & < 36-40 41-45 46 & > 

Ratings Received by Peer ATCSs 

N Mean S.D. N Mean s.o. N Mean s.o. N Mean s.o. N 

Peer Raters N 

Age 46 & > 11 20 4.63 .97 20 5.10 ,81 10 4.77 1,21 8 4.20 1,10 Age 36-45 59 137 4.91 ,89 105 5.22 ,82 32 4.45 .60 37 3,98 • 79 3

Age 35 & < 51 108 5.08 .92 119 5.18 .84 31 4.97 1.04 27 3.89 1.19 2

Total Sample* 121 265 4.96 .91 244 5.19 .82 73 4.72 .92 72 3.97 .98 65

*The data pertain to the RLGR Ratings obtained at several facilities from 121 ATCSs who deferred 

privilege. Each of the 121 rated four to seven peers, resulting in a total of 654 ratings from 145 AT

of ratings rendered _by ATCSs of age 35 and younger for coworkers of age 41 to 45 was significantly hig

than the mean of performance evaluations of the same group of ATCSs of age 36 to 45; no other mean RLG

within any ratee age group proved to be significant. The means of ratings by ATCSs of age 35 and youn

controllers under 36 and those 36 to 45 were significantly higher < .01) than their mean rating of 

older. The same was true with respect to ATCS raters aged 36 to 45; moreover, the latter also tended 

of age 41 to 45 significantly lower < .05) than those of all lower age brackets. A comparison of r

mitted by the very small number of ATCSs over 45 years of age revealed no significant mean differences 

ratee age groups. 
<:)l I 

Appendix 5. Means* of Supervisory RLGR Ratings by age level for Terminal ATCSs of dichotomized FAA 

experience groups "12 years or less" and "13 years or more." 

5.50 

Supervisory I 

5.00 

RLGR 

4.50 

Rating 

4.00 

Chronological Age 

N - 12 years & less 

He an 

S,D. 

N - 13 years & more 

He an 

S.D. 

N - comb. exp. grps. 

He an 

S ,D. 

• 

- • combined 

exp. groups 

30 & < 

30 

5.38 

.62 

30 

5.38 

.62 

31-35 

262 

5.30 

.82 

262 

5.30 

.82 

0 ....... 

36-40 

186 

5.17 

.83 

6 

4.92 

.72 

192 

5.16 

.83 

....... 

• 

....... 

0 

12 years 

or less 

FAA ATC 

experience 

12 6 <. 

comb. groupe • 

13 & > 0 

13 years \ -. 

/ 

or more • 

FAA ATC o '-._ 

experience'-

41-45 

27 

5.18 

.80 

16 

4. 76. 

.71 

43 

5.02 

.79 

46-50 

17 

4.20 

.84 

12 

4.12 

.84 

29 

4.17 

.82 

' ' • 0 

51 & > 

5 

4,57 

.79 

15 

3,78 

.89 

20 

3.97 

.91 

Tota

527 

5.2

.8

49 

4.3

.9

576 

5.1

.8

*Disregarding experience, differences between the mean ratings of each of the groups 

significant ATCSs of either age 30 and younger, 31-35, 36-40, or 41-45 versus those either 

or 51 and older. None of the differences between experience subgroups within age levels are signifi
<:..:> 

c.> 

Appendix 6. Means* of Supervisory RLGR Ratings by FAA ATC experience level for Terminal ATCSs of 

age groups "40 and younger" and "41 and older." 

• 

Superviaory 

_ ;;;:;;, • -- · age 40 age 

ombined ; ....- - • comb • 

0 • age groups o 

5.00 '- I '\. 

" ' . I ' I ' RLGR ' ' ' I 0 4. 50 ' I ' age 

' I age 41' • " & older', Rating • 0---.' 

• 

4.00 

Years FAA-ATC Exp. < 5 5-6 7-8 9-10 11-12 13-16 17-20 21 

N - Age 40 & < 6 45 91 194 142 6 

Mean 5.11 5.31 5.20 5.25 5.28 4.92 

S.D. .84 .69 ,88 .81 .81 .72 

N - Age 41 & > 2 5 19 23 15 16 . 12 

Mean 5.05 4.29 5.09 4.61 4.28 4.30 4.

S.D. 1.06 .91 .87 ,97 1.07 • 

N - Comb. age grps. 8 45 96 213 165 21 16 12 

Mean 5.09 5.31 5.15 5.24 5.18 4.46 4.30 4.

S.D. .79 .69 .91 .82 .85 .93 1.07 .

*In comparing the mean ratings of the experience groups, irrespective of age, differences a

(R<.05) for: ATCSs having either 5-6 or 9-10 years experience versus those having either 13-16, 

more years; ATCSs having 7-8 years versus those having 21 or more years; and ATCSs with 11-12 ye

versus those having either 17-20 or 21 or more years. For age subgroups within tenure levels, s

differences pertain to ATCSs with 7-8 and 11-12 years experience, 
<:>:> 

--l 

Appendix 7. Means* of Crew Chief RLGR Ratings by age level for Terminal ATCSs of dichotomized 

experience groups "12 years or less" and "13 years or more." 

Crew Chief 

5.50 • 

RLGR 

5.00 

Rating 

4.50 4.00 • 

Chronological Age 

N - 12 years & < 

Mean 

S.D. 

N - 13 years & > 

Mean 

S.D. 

N - comb. exp. grps. 

Mean 

S.D. 

-

. combined 

exp. groups 

30 & < 31-35 33 

5.50 

.63 

33 

s.so 

.63 

269 

5.46 

.so 

269 

5.46 

.so 

--

0 

\ 

\ 

\ 

\ 

12 years 

12 

comb. gro

• or less 

• !AA 

36-40 

194 

5.30 

.79 

6 

5.87 

.72 

200 

5.32 

.79 

\ 

\ 0 - 13 years --- • ...._ 

or more TC '' 

FAA A ...._ o experience • 

41-45 

27 

s.os 

.86 

15 

4.52 

• 74 

42 

4.86 

.85 

46-50 

17 

4.84 

.97 

12 

4.37 

.82 

29 

4.64 

.92 

51 & > 

4 

4.48 

• 74 

16 

4.14 

.90 

20 

4.21 

.87 

13 

*Disregarding experience, differences between the mean ratings of each of the following gr

significant ATCSs of either age 30 and younger, 31-35, or 36-40 versus those either 41

or 51 and older. None of the differences between experience subgroups within age levels are si
D:> 

00 

Appendix 8. Means* of Crew Chief RLGR Ratings by FAA ATC experience level for Terminal ATCSa o

age groups 11 40 and younger11 and 11 41 and older. 11 

Crew Chief 

5.50 

I 

RWR 

5.00 i 

Rating 

I 

4.50 

Years FAA-ATC exp. 

N - Age 40 & < 

Mean 

S.D. 

N - Age 41 & > 

Mean 

S.D. 

N - Comb. age grps. 

Mean 

s.D. 

I 

. 

• 

0 

-

< 5 

7 

4.83 

.67 

2 

4.68 

.71 

9 

4.80 

.64 

/ 

• 

z::::a • combined 

groups 

..,.. 

..,.. 

5-6 

48 

5.40 

.69 

48 

5.40 

• 69 

.., 

-0 

-

7-8 

90 

5.37 

.90 

6 

5.01 

.81 

96 

5.34 

.89 

-

& younger 

""· /

ge40 

_....o 

' 

9-10 

203 

5.46 

.74 

16 

5.15 

.82 

219 

5.44 

.7 5 

' 

I 

' ' 0 " 

age 41' ' 

• 

' , & older , 

11-12 

148 

5.37 

.82 

24 

4.78 

.97 

172 

5.28 

.86 

0 

' 

13-16 

6 

5.87 

.72 

15 

4.48 

.85 

21 

4.48 

1.02 

' ' ' • 

17-20 

15 

4.20 

1.00 

15 

4.20 

1.oo 

ag

comb

ag

21 

13 

4

13 

4

*In comparing the mean ratings of the experience groups, irrespective of age, differences 

for: ATCSs having either S-6, 7-8, 9-10, or 11-12 years experience versus those having 

21 or more years. For age subgroups within tenure levels, significant differences pertain to A

and 13-16 years experience. 
c.:; 

0 I 

Appendix 9. Means* of Coworker RLGR Batinga by age level for Terminal ATCSa of dichotomize

experience groups "12 years or less" and "13 years or more." 

Coworker I 

5.00 -1 

IW;R 

4.50 

Rating 

4.00 

Chronological Age 

N - 12 years & < 

Mean 

S.D. 

N - 13 years & > 

Mean 

S.D. 

• 

• 

combined --

exp. groups 

30 & < 31-35 

32 

5.22 

.53 

276 

5.18 

.65 

N - comb. exp. grps. 32 276 

5.18 

.65 

Mean 5.22 

S.D. .53 

-. 12· years 

0 

or leaa \ • FAA ATC 

\ \ '\. experience 

\ 

\ 

• 

1

comb: g

13 years \ 

or more \ 

FAA ATC o -

experience 

___ : ':---_ ' . 

' ' ' 

36-40 

199 

4.98 

.65 

6 

4.99 

1.05 

205 

4.98 

.66 

41-45 

28 

4.91 

.ss 

16 

4.18 

.71 

44 

4.64 

• 70 

46-50 

18 

4.34 

.64 

12 

4.22 

.so 

30 

4.29 

' . 0 

51 & > 

5 

4.21 

.64 

16 

3.94 

.69 

21 

4.00 

.67 

*Disregarding experience, differences between the mean ratings of each of the followin

significant ATCSs of age 30 and younger versus those either 41-45, 46-50, or 51 an

of age 31-35 versus those either 36-40, 41-45, 46-50, or 51 and older; those of age 36-40 v

either 46-50 or 51 and older; and those of age 41-45 versus the oldest group. Of the differ

experience subgroups within age levels, only that pertaining to ATCSs of age 41-45 is signi
I ' 

,.,. 

0 

Appendix 10. Means* of Coworker RLGR Ratings by FAA ATC experience level for Terminal ATCSs of 

age groups "40 and younger" and "41 and older." 

Coworker 

5.00 

RLGR 

4.50 • 

Rating 

4.00 

Years FAA-ATC Exp. 

N - Age 40 & < 

Mean 

S.D. 

N - Age 41 & > 

Mean 

S.D. 

N - Comb. age grps. 

Mean 

s.o. 

•• 

· 7 

• age groups •--

.,.., 0--- ---0 

< 5 

7 

4.99 

.54 

2 

4.65 

9 

4.91 

.so 

5-6 

45 

5.15 

.58 

45 

5.15 

.58 

7-8 

93 

5.23 

.68 

6 

4.68 

.80 

99 

5.19 

.70 

-

-0 

' 

9-10 

210 

5.08 

.65 

19 

4.84 

• 68 

229 

5.06 

.66 

' 

age 40 

-: --._ younger 

' ' 0 ' '\. . 

age 

comb

ag

age 41 ' """---

& o 1 der , --...._., • ---- ' -- 

11-12 

152 

5.06 

.63 

24 

4.47 

• 59 

176 

4.98 

.66 

. .,... 

--..-

13-16 

6 

4.99 

1.05 

15 

4.02 

.63 

21 

4.29 

.87 

17-20 

16 

4.15 

.83 

16 

4.15 

.83 

21 

13 

4

13 

4

*In comparing the mean ratings of the experience groups, irrespective of age, differences 

(£<.05) for: ATCSs having either 5-6, 7-8, 9-10, or 11-12 years experience versus those having 

17-20, or 21 or more years. For age subgroups within tenure levels, significant differences pe

with 11-12 and 13-16 years experience. 
H'>-

...... 

\ I 

Appendix 11. Means''' of Overall Radar Ratings by age level for Terminal ATCSs of dichotomize

experience groups "12 years or less" and "13 years or more." 

Overall 

5.00 

Radar 

4. 50 -

Rating 

4.00 .. 

Chronological Age 

N - 12 years & less 

Mean 

S.D. 

N - 13 years & more 

Mean 

S.D. 

N - comb. exp. grps. 

Mean 

S.D. 

. 

combined 

--

---

. -. 

exp. grps. 

30 & < 33 

5.28 

.44 

33 

5.28 

.44 

31-35 

280 

5.20 

0 59 

280 

5.20 

.59 

0 

_ 

• 12 years 

• or less 

FAA ATC 

\ 

\ 

13 • -

FAA ATC 

12 

comb. gr

- 0 

or more • - - - - : 

' 

13 

experience 

36-40 

199 

5.06 

.59 

6 

5.22 

.63 

205 

5.06 

0 59 

41-45 

28 

4.95 

0 59 

16 

4.47 

0 59 

44 

4.77 

.63 

46-50 

18 

4.45 

.55 

12 

4.37 

.59 

30 

4.42 

.56 

• 

51 & > 

5 

4.38 

.35 

16 

3.94 

.66 

21 

4.04 

.63 

*Disregarding experience, differences between the mean ratings of each of the following 

significant (£<.05): ATCS of either age 30 and younger or 31-35 versus those either 41-45, 46

and older ; those of age 36-40 versus those either 46-50 or 51 and older; and those of age 41-

the oldest group. Of the differences between experience subgroups within age levels, only th

ing to ATCSs of age 41-45 is significant. 
Appendix 12. Means* of Overall Radar Ratings by FAA ATC experience level for Terminal ATCSs of 

age groups "40 and younger" and "41 and older." 

age 40 

Overall & younger 

• . . 

----

. /: -· . -- ag

combined -14 • com

5.00 • 

• age groups 

Radar 

• 

/ 

_-·, ' '\ 

-- 0 ' --

0 

--- ' 0 

4. 50 ' • ag

age 41' " & older' Rating ' 0- ---· 

Years FAA-ATC Exp. < 5 5-6 7-8 9-10 11-12 13-16 17-20 21 

N - Age 40 & < 7 48 95 210 152 6 

Mean 4.90 5.16 5.15 5.16 5.14 5.22 

S.D. .53 .50 .67 .56 .59 .62 

N - Age 41 & > 2 6 19 24 15 16 13 

Mean 4.60 4. 73 4.89 4.59 4.23 4.25 4

S.D. .70 .62 .57 .73 .77 

N - Comb, age grps. 9 48 101 229 176 21 16 13 

Mean 4.83 5.16 5.12 5.14 5.06 4.51 4.25 4

S.D. .51 .50 .67 .57 .62 .82 .77 

---

*In comparing the mean ratings of the experience groups, irrespective of age, differences 

for: ATCSs having either 5-6, 7-8, 9-10, or 11-12 years experience versus those having 

17-20, or 21 or more years. For age subgroups within tenure levels, significant differences p

with 9-10, 11-12, and 13-16 years experience, 
I 

Appendix 13. Means* of Overall Local Ratings by age level for Terminal ATCSs of dichotomize

experience groups "12 years or less" and "13 years or more." 

Overall i 

I 

5.00 

Local 

4.50-

Rating 

4.00-

Chronological Age 

N - 12 years & < 

Mean 

S.D. 

N - 13 years & > 

Mean 

S.D. 

N - comb. exp. grps. 

Mean 

S.D. 

• -

--

. combined 

exp. grps. 

30 & < 

33 

5.32 

.50 

33 

5.32 

.50 

31-35 

280 

5.24 

.59 

280 

5.24 

.59 

0 

', 12 years 

• • or less 

FAA ATC 

', • 

13 years \, 

12 

comb. gro

or more "' • :--....._ 

FAAATC o -----; experience ' • 

' ' ' 

13 

36-40 41-45 46-50 

199 28 18 

5.09 5.02 4.54 

.56 .55 .53 

6 16 12 

5.26 4.55 4.45 

.59 .58 .57 

205 44 30 

5.09 4.85 4.50 

.56 .60 .54 

' . 

0 

51 & > 

5 

4.34 

.38 

16 

4.01 

.62 

21 

4.09 

.58 

*Disregarding experience, differences between the mean ratings of each of the following 

significant ATCSs of either age 30 and younger or 31-35 versus those either 41-45, 4

and older; those of age 36-40 yersus those either 46-50 or 51 and older; and those of age 41-4

the oldest group. Of the differences between experience subgroups within age levels, only th

ing to ATCSs of age 41-45 is significant. 
t 

Appendix 14. Means* of Overall Local Ratings by FAA ATC experience level for Terminal ATCSs of 

age groups "40 and younger" and "41 and older." 

age 40 

& younger 

Overall • ......._; . a

. --- . -.... . 

/cod>ined ..... .._. com

5.00 age groups ',,." • • -- 0 - Local 0 ----- ' • a

4.50 • age 41 ', ' & older , . ---· 

Rating 

Years FAA-ATC exp. < 5 5-6 7-8 9-10 11-12 13-16 17-20 2

N - Age 40 & < 7 48 95 210 152 6 

Mean 4.94 5.26 5.20 5.19 5.16 5.26 

S.D. .46 .47 .67 .57 .56 .59 

N - Age 41 & > 2 6 19 24 15 16 

Mean 4.74 4.81 4.95 4.65 4.32 4.34 

S.D. .44 .60 .63 .56 .66 .78 

N - Comb. age grps. 9 48 101 229 176 21 16 

Mean 4.90 5.26 5.18 5.17 5.09 4.59 4.34 

S.D. .44 .47 .67 .57 • 59 • 76 .78 

--------

*In comparing the mean ratings of the experience groups, irrespective of age, differences a

(£<.05) for: ATCSs having either 5-6, 7-8, or 9-10 years experience versus those having either 

21 or more years and ATCSs having 11-12 years experience versus those having 17-20 or 21 or more 

subgroups within tenure levels, significant differences pertain to ATCSs with 11-12 and 13-16 ye
C< 

Appendix 15. Means>'< of Overall General Ratings by age level for Terminal ATCSs of dichotom

experience groups "12 years or less" and "13 years or more." 

5 .so -

........... Overall '-

combined • -.,_ 

exp. grps. --...,., _____ & ------ 12 years 

0 

'-.._--- • or less comb. g

, • experience 5.00 • , "' ATC 

General ' 

13 years ' • - - · 

or more '-

• 

4 S FM ATC - • -.. 

· 0 - experience - -.... 4 • 

....... 

---- 0 

Rating 

Chronological Age 30 & < 31-35 36-40 41-45 46-50 51 & > 

N - 12 Years & less 33 280 199 28 18 5 

Mean 5.44 5.28 5.19 5.08 4.69 4.75 

S.D. .44 .61 .61 .63 .65 .57 

N - 13 Years & more 6 16 12 16 

Mean 5.06 4.58 4.38 4.42 

S.D . .92 .65 .67 .64 

N - comb. exp. grps. 33 280 205 44 30 21 

Mean 5.44 5.28 5.18 4.90 4.57 4.50 

s·.D. .44 .61 .62 .67 .67 .63 

>'<Disregarding experience, differences between the mean ratings of each of the followin

significant ATCSs of age 30 and younger or 31-35 versus those either 41-45, 

and older and those of age 36-40 versus those either 46-50 or 51 and older. Of the differe

experience subgroups within age levels, only that pertaining to ATCSs of age 41-45 is signi
.... 

0:> 

Appendix 16. Means''< of Overall General Ratings by FAA ATC experience level for Tenninal ATCSs 

age groups "40 and younger" and "41 and older." 

. . 

-

Overall /combined- • 'iiiiiiiiiiiiiiiii ' iiii;...,__-- • age 40 ag

"'-6. younger comb

age groups o • 

5.00 ° 

. 

- -

--

/ 

/ /' ' ' \' 

-.... / ' 

Genera 1 ° o ' ag

4.50 age 41 ' , . ---.. .. z;:.- • • 

& older ' - .-

Rating 

Years FAA-ATC Exp. < 5 5-6 7-8 9-10 11-12 13-16 17-20 21 

N - Age 40 & < 7 48 95 210 152 6 

Mean 5 .00 5 , 32 5.30 5.26 5.21 5.06 

S.D. .48 .57 ,61 .58 ,64 .92 

N - Age 41 & > 2 6 19 24 15 16 13 

Mean 5.03 4.77 5.17 4.73 4.38 4.50 4,

S.D. .83 .52 .67 .53 .89 ,

N - Comb. age grps. 9 48 101 229 176 21 16 13 

Mean 5.00 5.32 5.27 5.25 5,14 4.57 4.50 4.

S.D. .44 .57 ,63 .58 .66 .71 ,89 .

*In comparing the mean ratings of the experience groups, irrespective of age, differences 

(.£<.05) for: ATCSs having either S-6, 7-8, .or 9-10 years experience versus those having either 

or 21 or more years and ATCSs having 11-12 years experience versus those having either 13-16 or 

For age subgroups within tenure levels, significant differences pertain to ATCSs with 7-8 and 

years experience. 
......... 

Appendix 17. Means* of Overall Relative Proficiency Ratings by age level for Terminal ATCSs o

mized FAA ATC experience groups "12 years or less" and "13 years or more." 

5.50 • 

Overall 

5.00. 

Relative 

4.50. 

Proficiency 

4.00 

Rating 

3.50. 

Chronological Age 

N - 12 years & < 

Mean 

S,D, 

N - 13 years & > 

Mean 

s.D. 

N - comb. exp. grps, 

Mean 

s.D. 

0 

exp. • 

12 & 

comb. group

• ... " , 

\ 12 yeara 

'3o & < 

33 

5.51 

,66 

33 

5.51 

.66 

31-35 

280 

5.52 

.90 

280 

5.52 

.90 

\ 

\ 

\ 

13 years 

or more 

\ 

\ 

\ 

\ 

0 

FAA ATC 

experience ' 

36-40 

199 

5.27 

,93 

6 

5.51 

.87 

205 

5.28 

.92 

41-45 

28 

5.14 

.80 

16 

4.35 

.86 

44 

4.85 

.90 

or less 

FAA ATC 

experience 

' ' . - -. '\."' ...... 

46-50 

18 

4.16 

.83 

12 

3.72 

.91 

30 

3.99 

.87 

' ' ..... 

D 

51 & > 

5 

4.12 

.47 

16 

3.48 

1.10 

21 

3.63 

1.01 

13 & 

>':Disregarding experience, differences between the mear ratings of each of the following gro

significant (£<.05): ATCSs of either age 30 and younger, 36-40, or 41-45 versus those either 46

and older and ATCSs of age 31-35 versus those either 41-45, 46-50, or 51 and older. Of the diff

between experience subgroups within age levels, only that pertaining to ATCSs of age 41-45 is s
00 

. 

c 

'!' 

Cl 

0 

< 

"' "' z 

3: 

"' z 

.., 

"' 

z 

.., 

z 

C1 

0 

"' ., n 

"' 

:;:; 

"' 0 I 

"' 

I 

0 

0 

;:; 

0 0 

0 

Appendix 18. Means* of Overall Relative Proficiency Ratings by FAA ATC experience level for Term

dichotomized age groups "40 and younger" and "41 and older." 

5.50 

Overall 

5.00 

Relative 

4.50 

Proficiency 

4.00 

Rating 

Years FAA-ATC Exp. 

N - Age 40 & < 

Mean 

S.D. 

N • Age 41 & > 

Mean 

S.D. 

N - Comb. age grps , 

Mean 

S.D. 

• 

. -· / combined age groups 

• 

• 

< 5 

7 

5.02 

. 70 

2 

4.80 

9 

4.97 

. 75 

5-6 

48 

5.40 

.72 

48 

5.40 

.72 

/ 

- 0 

7-8 

95 

5.44 

1.06 

6 

4 , 68 

.73 

101 

5.39 1.06 

/ 

0 

/ ' 

9-10 

210 

5.45 

.85 

19 

4.87 

.93 

229 

5.40 

. 87 

' 

. 

.--&ge 40 

' ' 

• 

& younger 

\. . 

age 41 \.. 

& older \.. 

11-12 

152 

5.40 

.93 

24 

4.55 

.96 

176 

5 .29 

.98 

\. 

\. 

0 

13-16 

6 

5.51 

.87 

15 

4.04 

1.07 

21 

4.46 

1.21 

' 

17-20 

16 

3.81 

1.27 

16 

3.81 

l. 27 

ag

comb

ag

21 & 

13 

3. 7

.5

13 

3.7

.5

*In comparing the mean ratings of the experience gro

ups, irrespective of age, differe nc es a

(£ <'· 05) for: ATCSs having either 5- 6 , 7-8, 9-10, or 11-12 

years experience vers

us those !Javi 1!g e

17-20, or 21 or more 

years. For age subgro

ups witi1 i n tenure levels, differe nces per

with 9-10, 11-12, a nd 13-lb years experience. 


istration, Office of Aviation 

cal Institute, Oklahoma City, 

TIONSHIPS OF AGE AND 

O JOB PERFORMANCE 

AL AREA TRAFFIC CON

Cobb, Peter L. Nelson, and 

 1973, 48 pp. Report No. 

collection of experimental ratings of 

er data for several hundred journey

ialists of 17 high-IFR-traffic-density 

ontrol facilities. Significant inverse 

d between the job ratings and both 

nure in FAA ATC' work. Results of 

of data for dichotomized groups aged 

41 and older" within each of several 

pings indicated that ( 1) the younger 

ence level tended to receive higher 

\·er 40 years old, and (2) the greater 

rformance ratings pertained to thP. 

s having over 10 years experience. 

analysis indicated that, when the 

oretically nullified, or held constant, 

nly negligibly with verformance. A 

d that if the subjects had possessed 

erienee, their ratings would still have 

nd so, with their ages. 

sted that ATCS more 

 of factors associated with aging than 

umed effects f•·om lengthy 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J . 

Descriptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings 

Federal Aviation Administration, Office of Aviation 

Medicine, Civil Aeromedical Institute, Oklahoma City, 

Oklahoma. THE RELATIONSHIPS OF AGE AND 

ATC EXPERIENCE TO JOB PERFORMANCE 

RATINGS OF TERMINAL AREA TRAFFIC CONTROLLERS by Bart B. Cobb, Peter L. Nelson, and 

John J. Mathews, April 1973, 48 pp. Report No. 

FAA-AM-73-7. 

Thi;' study involved the collection of experimental ratings of 

job performance and other data for several hundred journeymen rada r control specialists of 17 high-IFR-traffic-density 

'l'erminal Area Traflic Control facilities. Significant inverse 

relationships were found between the job ratings and both 

chronological age and tenure in FAA ATC' work. Results of 

a comparative analysis of data for dichotomized groups aged 

"40 and younger" and "41 and older" within each of several 

length-of-experience groupings indicated that (1) the younger 

subjects of every experience level tended to receive higher 

evaluations than those over 40 years old, and (2) the greater 

mean differences in performance ratings pertained to the 

dichotomized age groups having over 10 years experience. 

However, a regression analysis indicated that, when the 

variance of age was theoretically nullified, or held constant, 

experience correlated only negligibly with performance. A 

similar analysis indicated that if the subjects had possessed 

identical amounts of experience, their ratings would still have 

correlated negatively, and significantly so, with their ages. 

Other results also suggested that ATCS proficien(·y is more apt to decline as a result of factors associated with aging than as a consequence of presumed effects stemming from lengthy 

AT(' experience. 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J. 

Descriptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings 

. -.--------------------------------------------
---------------·---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

tration, Office of Aviation 

l Institute, Oklahoma City, 

IONSHIPS OF AGE AND 

O JOB PERFORMANCE 

L AREA TRAFFIC CON

Cobb, Peter L. Nelson, and 

1973, 48 pp. Report No. 

ollection of experimental ratings of 

r data for several hundred journey

lists of 17 high-IFR-traffic-density 

ntrol facilities. Significant inverse 

between the job ratings and both 

ure in FAA A'.rC' work. Results of 

data for dichotomized groups aged 

 and older" within each of several 

ngs indicated that (1) the younger 

nce level tended to receive higher 

r 40 years old, and (2) the greater 

ormance ratings pertained to the 

having over 10 years · experience. 

nalysis indicated that, when the 

retically nullified, or held constant, 

y negligibly with performance. A 

that if the subjects had possessed 

ience, their ratings would still have 

 significantly so, with their ages. 

ed that ATCS proficiency is more 

f factors associated with aging than 

med effects stemming from lengthy 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J . 

Descriptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings 

Federal Aviation Administration, Office of Aviation Medicine, Civil Aeromedical Institute, Oklahoma City, 

Oklahoma. THE RELATIONSHIPS OF AGE AND 

ATC EXPERIENCE TO JOB PERFORMANCE 

RATINGS OF TERMINAL AREA TRAFFIC CONTROLLERS by Bart B. Cobb, Peter L. Nelson, and 

John J. Mathews, April 1973, 48 pp. Report No. 

FAA-AM-73-7. 

This study involved the collection of experimental ratings of 

job performance and other data for several hundred journeymen radar control specialists of 17 high-IFR-traffic-density 

Terminal Area Traffic Control facilities. Significant inverse 

relationships were found between the job ratings and both 

chronological age and tenure in FAA ATC' work. Results of 

a comparative analysis of data for dichotomized groups aged 

"40 and younger" and "41 and older" within each of several 

length-of-experience groupings indicated that (1) the younger 

subjects of every experience level tended to receive higher 

evaluations than those over 40 years old, and (2) the greater 

mean differences in performance ratings pertained to the 

dichotomized age groups having over 10 years experience. 

However, a regression analysis indicated that, when the 

variance of age was theoretically nullified, or held constant, 

experience correlated only negligibly with performance. A 

similar analysis indicated that if the subjects had possessed 

identical amounts of experience, their ratings would still have 

correlated negatively, and significantly so, with their ages. 

Other results also suggested that ATCS proficiency is more 

apt to decline as a result of factors associated with aging than as a consequence of presumed effects stemming from lengthy 

ATC experience. 

I. Cobb, B. B. 

II. Nelson, P. L. 

III. Mathews, 

J. J. 

Descriptors 

Aging Effects 

Work Experience 

Effects 

Air Traffic 

Controllers 

Job Ratings 

Peer Ratings