16

Retention of Military Knowledge and Skills | e=2===========

The UDA process was not designed to address the difficulty
of learning a task or how to conduct training. It focuses on
task characteristics and does not take into account any
techniques or strategies used during initial training or during
the retention period to counteract forgetting. (These issues
will be discussed in a later section.) Figure 8 displays a
flowchart for the rating process.

The Army conducted an extensive validation study of the
UDA on 22 tasks for the Cannon Crewman MOS.* Each
task was rated by five task experts; the inter-rater reliability
was high (average correlation greater than .90). That is,
there was strong agreement among the answers the raters
gave for particular tasks. Soldiers were trained to 100%
proficiency on all tasks, and retention tests were given at
intervals of 2,5, and 7 months. The UDA scores accurately
predicted retention performance (percent of soldiers
performing at a “Go” level) at all three intervals, with the
best accuracy (correlation greater than .90) at the 2-month
interval.

The study also compared the UDA to another approach for
predicting performance — directly measuring task difficulty
by determining what percentage of soldiers performed at a
“Go” level on their first attempt at the task immediately
after training. The results showed that the UDA and this
“acquisition performance” measure were about equally
accurate as predictors of retention at each retention interval
(all correlations greater than .60), with the UDA noticeably
the better predictor at the shortest interval. The researchers
argued that the UDA is more cost effective, since it can be
applied on a few subject matter experts without requiring
the collection of large amounts of acquisition performance
data. The UDA can be applied even to proposed tasks and
can provide predictions of retention even before any
widespread training has been given.

Since its development, the UDA has been applied
successfully to tasks in a number of military specialties,
including vehicle mechanicsTM, radio and communication
network operators*, quartermasters'’, combat engineers and
masonry/carpentry specialists®, field medics and air defense
missile crews?’, as well as to the tasks involved in peace
support operations.*® ARI has plans to continue research
using the UDA. Studies will be conducted, in the near
future, on the applicability of the UDA to predicting the
retention of digital skills, those needed by soldiers who operate
the Army’s increasingly complex computer-based systems.”

Excelient

One Step

Job Aids
Intended to Be

Quality of the
Job Aid

Many Steps
Are Required

Rate Required
Step Sequence

7

Rate Built in Task|
Step Feedback

7

Rate Task
Time Limit

¥

Rate Task Mental
Requirements

Many Facts,
Terms Must Be

Rate Difficulty of
Facts, Terms to
Remember

Y

(Control Demands

[Rate Motor

I
!
1
t
!
ee |

Consider

impact of
Job Aid

—---4—

Figure 8. Flowchart for predicting

task retention.



10

Retention of Military Knowledge and Skills

constitute most of the tasks trained by the Army. For example, a similar
wide range of retention was found for procedural tasks and instrument-
flying skills needed by helicopter pilots, although their basic (perceptual-
motor) flying skills were retained well.’ Some way to account for this
wide range of resistance to forgetting is needed. ARI’s approach to this
problem is described below.

Factors AFFECTING PROcEDURAL SKILL RETENTION

The inconsistency among individual studies of procedural skills occurs
because a number of factors that affect forgetting vary from one study to
the next. In the following sections, research is discussed in turn that
identifies two classes of factors — task factors and individual soldier
factors.

Task Factors

Forgetting of a procedural task is affected by four factors that relate to
the task itself: (1) how complex the task is, (2) how great the task
demands are for knowledge, decision, and execution, (3) whether a good
job aid is available as the soldier performs the task, (4) whether the task
is performed under the stress of a time limit. After describing these
factors below, we will show how ARI research integrated the factors into
a method for predicting memorability of individual tasks.

Task Complexity

Three primary factors combine to determine a value we will call task
“complexity.” This overall measure turns out to be highly predictive of
whether a task will be forgotten. A complex task is the opposite of one
with an inherent organization that produces a “simplicity” or unity, where
each task step follows logically or naturally from the one before.“ The
component factors are: (1) how many steps there are in the task,

(2) whether the steps must
be performed in a set
sequence, and (3) whether
there is built-in feedback
that indicates correct
performance of task steps.

NumBer OF TASK STEPS. Several
studies have shown that, as
the number of task steps
increases, retention
performance decreases.”
The best example of this
effect is an ARI study of
more than 500 soldiers
performing tasks learned in



20

Retention of Military Knowledge and Skills

would for most of the tasks studied; after many months without practice,
they were at the far right of the curves in Figure 5.

A subsequent ARI study involved mobilized IRR soldiers who had been
field medics.** Again, the length of time a soldier had been separated
from active duty did not have much predictive value, although aptitude
and length of active duty did. Civilian occupation turned out to be
important, since soldiers whose civilian jobs were in the medical field
(e.g., hospital worker or emergency ambulance technician) showed little
skill decay for their medical military tasks. However, for those medics
mobilized from non-medical civilian jobs, the set of AFQT scores was a
strong predictor of their ability to perform medic tasks, even before any
retraining was given.

The same predictive power of AFQT scores was reported for retention of
common task performance by soldiers mobilized from the IRR“, but
only for those who had previously spent a full two-year tour on active
duty. Once again, among soldiers given repeated opportunity to learn and
practice their tasks, followed by a long period without practice, the
higher-aptitude soldiers could recall the tasks significantly better. This
effect may be due directly to increased original learning or indirectly to
better retention. Either way, it exemplifies the interplay of aptitude and
opportunity to learn that yields the benefit of “overlearning.”

IMPROVING SKILL RETENTION

The ultimate goal of all this research is to provide Army trainers with
information they can use to improve soldiers’ retention of knowledge and
skills. Several methods for doing so follow.

Optimize the Schedule of Refresher Training

For soldiers deployed to Bosnia and Hungary as part of Operation Joint
Endeavor, ARI developed a Trainer’s Guide for Refresher Training
(Figure 10) that, on the basis of results from the UDA, ranked 27 tasks
needed for this operation in terms of their vulnerability to decay.”! For
example, the tasks “Extraction from Minefield” and “React to Civilian
on Battlefield” were predicted to show major problems due to decay after
only two months without practice. This information was provided so that
those in charge of training for these soldiers could foresee when skills
would decline below acceptable levels; they could thus create an optimal
schedule for their soldiers’ refresher training.

Maximize Original Learning

Another research-based approach available to trainers and training
managers for improving skill retention is to maximize the amount of
original learning that soldiers carry with them from their initial training.

“Amount of

original
learning or

overlearning...

during
training is the
best predictor
of how good...
skill retention

will be.”


Every year the Army trains soldiers on over 40,000 tasks. The more
complex tasks, such as repair of a radio communications system, may
require several weeks of training per soldier. The Army assumes that the
huge budget of time and money needed for this training is an investment
that will pay off in later job performance. That is, soldiers will retain the
knowledge and skills they acquire in training long enough to perform
effectively in their career assignments.

However, people forget and skills get rusty. A century of research on
memory' has shown that large amounts of forgetting can occur naturally
over periods as short as several hours or as long as many years.”? This
report reviews what is known about forgetting as it applies to military
tasks, concentrating on major projects conducted by the U.S. Army
Research Institute (ARI) during the past three decades. Included are both
basic research supported by ARI at universities*> and applied studies
conducted in field settings by ARI researchers and by the Air Force and
Navy. This review will make clear several ways the Army can minimize
or reverse forgetting’s effects.

U.S. Army Research Institute



U.S. Army Research Institute

Individual Factors

In addition to the factors captured by the UDA, two others that affect
forgetting of procedural tasks are tied to the individual soldier: (1)
original learning (mostly a matter of training time, how much
opportunity the soldier has had to learn the task in the past) and (2)
aptitude (an individual difference factor, how strong an “aptitude for
learning” the soldier brings to the task situation). As one might expect,
these two strongly interact.

Original Learning

“Original learning” refers to the amount of knowledge and skill the
trainee has acquired by the end of training but before a job assignment.
In military courses, original learning can range from just passing a course
with a grade of 65 or 70 percent, to continuing to practice and learn even
after reaching a criterion of 100 percent (e.g., field stripping an MI6A1
rifle), Practicing a task after it has been learned well enough to be
performed correctly is referred to as “overlearning.” The level or degree
of original learning is probably the most significant single factor
affecting forgetting®; in particular, a task that is “overlearned” turns out to
be highly resistant to decay.”

For example, an ARI study of electrical repairers found that increasing
the number of training sessions on a complicated test station reduced
both performance time and errors two weeks after training.*! Another ARI
study of training to boresight and zero the main gun of the M60A1 tank
compared soldiers trained to one correct performance with soldiers
trained to three successive correct performances. After five weeks with
no practice, the group trained to three correct performances had fewer
errors.”

EE <I merece



“The problem

of retention
then becomes
the problem
of skill
reacquisition
during a ‘rapid

train-up’.”

U.S. Army Research Institute

SKILL REACQUISITION

Despite the best efforts of Army trainers and their use of proven
techniques for optimizing retention, soldiers will still experience decay
of their military knowledge and skills. Personnel called to duty from the
IRR or active duty soldiers deployed overseas may have lost sharpness
because of a lack of practice opportunities in the months (or even years)
preceding activation or deployment. The problem of retention then
becomes the problem of skill reacquisition during a “rapid train-up.”

ARI was asked to address this issue in 1993. In addition to assessing the
extent of skill decay in both active duty and IRR soldiers, ARI
researchers began to develop guidelines for retraining and for predicting
how rapidly skills can be reacquired.

This research program was based on the earlier work on skill retention
described above,” especially the results for medics mobilized to active
duty from civilian jobs in the medical field. The finding that civilian jobs
strongly affected retention of military skills led ARI researchers to
explore strategies for reestablishing job context for IRR soldiers. The
researchers reasoned that soldiers whose civilian jobs were similar
(although not identical) to their military specialties did not need time to
reinstate the “frame of mind” or job context required for their military
tasks. If job context could be reestablished for IRR soldiers by using
exportable technology, such as computer-based training or videotape
presentations, the time required for reacquisition training could be
reduced.

To test this hypothesis, the researchers prepared two different videotape
presentations that showed two sets of three medical-related common
tasks being performed in accordance with the 1994 Soldier’s Manual of
Common Tasks. One video was shown to half of a sample of 100
soldiers, and the other video was shown to the remaining half. Several
days later, all soldiers performed all six tasks.

The demographic findings were consistent with the previous IRR studies:
(1) Soldiers who had completed a full tour of active duty performed
better than those who had received only a few months of MOS training,
(2) soldiers with above-average aptitude performed better, and

(3) retention interval had little effect on performance. Performance for
tasks shown on the videotape was significantly better than for tasks not
shown; on some tasks, performance differences were as great as 30
percent.

Exposure to a simple five-minute presentation thus had a dramatic effect
on task performance, apparently by re-establishing job context for the
mobilized soldiers. Many reported that the videotapes were “very
useful,” in that they “brought back a lot” of task knowledge. On the basis
of these results, the researchers proposed that videotape and similar
technologies (e.g., internet-based training) could be employed in future
mobilizations to shorten the time required for reacquisition.**

23



Figure 9. Soldier aptitude and
memory for basic training tasks.

U.S. Army Research Institute

——@—— Low Aptitude —I Intermediate Apfitude — de = High Apftude
100 5
= 90
: .
= 80 ~
— N
S
5 70
a
%
& 60
50 T 1
Initial Training Six Weeks
Time of Test

This effect was shown in the already-mentioned study (Figure 4) of IRR
soldiers called to duty for Operation Desert Storm.“ Demographic data
(e.g., time since separation from active duty, aptitude, length of active
duty, and civilian occupation) as well as performance data were collected
on thousands of soldiers from more than 25 MOSs. Performance
measures included both written job knowledge tests and hands-on
performance tests. The researchers found that the best predictor of skill
retention for an individual was the amount of overlearning, as measured
by a combination of aptitude (AFQT score) and time on active duty.

High-aptitude trainees, by definition, learn more quickly than do their
lower-aptitude peers. Further, the more time soldiers, of any aptitude
level, spend on active duty, the more opportunities they have to practice
the knowledge and skills acquired in training. Therefore, both high
aptitude and long active duty time are predictive of the experience of
overlearning; and this experience of overlearning is predictive of
resistance to forgetting.

This expectation was confirmed when both groups — soldiers with high
aptitude and those with long prior active duty — did well on the
measures of skill and knowledge retention, before any retraining was
given. Also, as expected, soldiers with both high aptitude and long prior
service did best. The surprising finding was that the length of time
between separation from active duty and the IRR call-up (i.e., the
retention interval) had little effect on forgetting. Increased length of
separation was only a weak predictor of a decline in retention
performance; the other predictors — lower aptitude and shorter active
duty — were much stronger predictors of performance decline. The lack
of a retention interval effect here is explained by assuming that most of
the IRR soldiers had already suffered most of the forgetting they ever



14

Retention of Military Knowledge and Skills

Job and Memory Aids

These aids, designed to facilitate job performance by minimizing the
need for recall, come in all shapes and sizes. Some memory aids are
taught to soldiers in training; for example, S-A-L-U-T-E is included as a
mnemonic device in the Soldier’s Manual of Common Tasks. By
providing retrieval cues, it helps soldiers to remember that, when
completing the task Report Enemy Information, they should include
information on the enemy’s Size, Activity, Location, Unit, Time, and
Equipment. Job aids include technical manuals that are meant to be used
on the job, instructions printed on forms detailing what information goes
where, and labels with start-up instructions attached to equipment. Most
maintenance tasks require use of technical manuals as job aids, and many
operator tasks involve job aids in the form of checklists to ensure that the
equipment is ready for operation.

But job and memory aids vary in quality. A truly effective job aid allows
the user to perform the entire task with no additional information or help.
Such an aid is clearly written, using terminology familiar to the typical
user, and easy for the soldier to use while performing the task. A poor job
aid, on the other hand, requires the user to have additional expertise or
information to perform the task; it only really helps someone who mostly
has no need for it.



Retention of Military Knowledge and Skills =

Figure 3. Average data from 40
studies of memory for school
100 - ” knowledge.
= 80 —~§—————@
rs
3 60 +— — |
3 |
3 |
s 40 E
E }
2 |
& 20 :
I
F
0 7 T a }
1 to 13 14 to 26 >26 |
Retention Interval (weeks)

Several military studies contributed to the results in Figure 3. For
example, a study of recognition memory for propulsion engineering
training at the Navy’s training center at Great Lakes, Illinois, found that
trainees remembered 91 percent after 4 weeks and 80 percent after 28
weeks."

As mentioned above, procedural tasks constitute a special class among
tasks that rely heavily on knowledge retrieval. Because procedural tasks
require the soldier to produce a set of actions, they tend to suffer from
the degradation over time seen in Figure 3 for performance measured by
recall. An Air Force study, for example, looked at procedural skill loss
among airmen while they were in the Individual Ready Reserve (IRR);
among those separated from active duty for 18 to 24 months, only 53%
retained proficiency.’

Such procedural tasks are
knowledge-dependent, because
they require retrieval of
memory, both for the steps that
must be performed and, in
some cases, for the order in
which they must be done. From
another perspective, however,
these tasks also form a bridge
to the class of tasks, discussed
below, for which well-practiced
execution is key.



26

Retention of Military Knowledge and Skills = = <=

REFERENCES

1.

20.

21.

22.

23.

24.

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 Dunker, Translation by H. Ruyer & C, Bussenius, Memory. New York: Teachers

Ebbinghaus, H. (1885). Uber das Geddchtnis. Leipzi
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Arthur, W., Bennett, W., Stanush, P., & McNelly, T. (1998). Factors that influence skill decay and retention: A quantitative review and
analysis. Human Performance, M1, 1, 57-101.

Farr, M. (1987). The long-term retention of knowledge and skills: A cognitive and instructional perspective. New York: Springer-Verlag.
Healy, A., Ericsson, K., & Bourne, L., Jr. (1987). Optimizing the long-term retention of skills: Structural and analytic approaches to skill
maintenance (Research Note 87-53). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Jones, M. (1986). Non-imposed practice and skill retention (Research Note 86-55). Alexandria, VA: U. S. Army Research Institute for the
Behavioral and Social Sciences.

Allen, G., Secundo, M., Salas, E., & Morgan, B., Jr. (1983). Evaluation of rate parameters of the acquisition, decay, and reacquisition of
complex cognitive skills (Technical Report ITR-82-27). Norfolk, VA: Old Dominion University, Center for Applied Psychological Studies.
Fleishman, E., & Parker, J., Jr. (1962). Factors in the retention and relearning of perceptual motor skill. Journal of Experimental
Psychology, 64, 205-226.

Gabrieli, J. (1998). Cognitive neuroscience of human memory. Annual Review of Psychology, 49, 87-115.

Semb, G., & Ellis, J. (1994). Knowledge taught in school: What is remembered? Review of Educational Research, 64, 3, 253-286.

Wetzel, S., Konoske, P., & Montague, W. (1983). Estimating skill degradation for aviation antisubmarine warfare operators (AWs): Loss
of skill and knowledge following training (Technical Report NPRDC TR 83-31). San Diego: Navy Personnel Research and Development
Center.

Austin, S., & Gilbert, K. (1973). Student performance in a Keller-Plan course in introductory electricity and magnetism. American Journal
of Physics, 41, 82-87.

Conway, M., Cohen, G., & Stanhope, N. (1991). On the very long-term retention of knowledge acquired through formal education: Twelve
years of cognitive psychology. Journal of Experimental Psychology: General, 120, 395-409.

ifty years of memory for Spanish learned in school. Journal of Experimen-

Bahrick, H. (1984). Semantic memory content in permastor
tal Psychology: General, 113, 1-29.

Ellis, J. (1980). Long-term retention of factual information (Technical Note NPRDC TN-80-5). San Diego: Navy Personnel Research and
Development Center.

Davis, M. (1991). Determination of skill degradation rates and retraining requirements by AFSC: Phase Il. Alexandria, VA: Human
Resources Research Organization.

Schendel, J., & Shields, J. (September 1978). Retention of motor skills: A review (Technical Report 313). Alexandria, VA: U. S. Army
Research Institute for the Behavioral and Social Sciences.

‘Adams, J. (1987). Historical review and appraisal of research on the learning, retention, and transfer of human motor skills. Psychological
Bulletin, 101, 1, 41-74.

Wick, D., Millard, S., & Cross, K. (January 1986). Evaluation of a revised Individual Ready Reserve (IRR) aviator training program:
Final Report (Technical Report 697). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Wisher, R., Sabol, M., Sukenik, H., & Kern, R. (1991). Individual Ready Reserve (IRR) call-up: Skill decay (Research Report 1595).
Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences

McKenna, S., & Glendon, A. (1985). Occupational first aid training: Decay in cardiopulmonary resuscitation (CPR) skill. Journal of
Occupational Psychology, 58, 109-117.

Vineberg, R. (1975). A study of the retention of skills and knowledge acquired in basic training (Technical Report 75-10). Alexandria,
VA: Human Resources Research Organization.

Wisher, R., Sabol, M., Maisano, R., Knott, B., Curnow, C., & Ellis, J. (1996). Retraining medics for mobilization. Paper presented to the
‘American Educational Research Association, San Diego, CA.

Prophet, W. (October 1976). Long-term retention of flying skills: A review of the literature (Final Report FR-ED(P) 76-35). Alexandria,
VA: Human Resources Research Organization.

Naylor, J., Briggs, G., & Reed, W. (1968). Task coherence, training time, and retention interval effects on skill retention. Journal of
Applied Psychology, 52, 386-393.

Knerr, C., Harris, J., O’Brien, B., Sticha, P,, & Goldberg, $. (1984). Armor procedural skills: Learning and retention (Technical Report
621, ADA1532274XSP). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Shields, J., Goldberg, G., & Dressel, J. (1979). Retention of basic soldiering skills (Research Report 1225). Alexandria, VA: U. S. Army
Research Institute for the Behavioral and Social Sciences.

Miller, G. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological
Review, 63, 81-97.

Hagman, J., & Rose, A. (1983). Retention of military tasks: A review. Human Factors, 25, 199-213.

Konoske, P., & Ellis, J. (1991). Cognitive factors in learning and retention of procedural tasks. In R.F. Dillon & J.W. Pellegrino (Eds.),
Instruction: Theoretical and applied perspectives (pp. 47-10). New York: Praeger.

Rose, A., Radtke, P., Shettel, H., & Hagman, J. (1985). User’s manual for predicting military task retention (Research Product 85-26).
Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences. (AD A163710).



Figure 1. Brain areas that control
different types of skills.

U.S. Army Research Institute

sometimes called cognitive processing — dominates in such tasks as
trouble-shooting faulty equipment and tactical decision-making by
officers. These are often referred to as cognitive tasks. In still other
tasks, precise execution of well-practiced actions is the crucial aspect;
such tasks are referred to in the psychological literature as perceptual-
motor tasks.’ The prime example is target acquisition and tracking.

Recent work in the neuroscience of human memory * indicates that these
three types of abilities are located and controlled in different regions of
the brain (Figure 1): verbal knowledge is encoded in the neocortex,
usually in the left hemisphere; cognitive tasks are performed primarily in
the frontal lobe; and the skilled execution of perceptual-motor tasks is
mediated by the cerebellum. As they are dependent on different areas of
the brain, it is not surprising that the studies described below have shown
a different pattern of forgetting for each type.

Execution
Decision Job Skills
Skills Knowledge Memory for
Memory for Memory for Perceptual-motor
Cognitive Tasks Procedural Tasks Tasks



Retention of Military Knowledge and Skills

How Mucu is REMEMBERED FOR How Lona?

Because forgetting may occur over any period when knowledge is not
applied and skills are not practiced, Army planners and trainers need
answers to the following questions:

1. How fast does forgetting occur for different kinds of skills?
2. Are some individuals more likely to forget than others?

3. What instructional strategies are effective in reducing
forgetting?

4. How difficult will it be for soldiers to reacquire skills they
have forgotten?

Answers to these questions are important for the development of
effective initial and refresher training programs, mobilization policy, and
reserve component training plans. This report addresses each question in
turn.

The Different Kinds of Skills

As soldiers attempt to perform an already-trained military task, they rely
on several different abilities. Consider a sports analogy: a quarterback
whose coach has called in a pass play. The main task has been set, but
three component tasks must be performed to successfully complete it. As
the team huddles, the quarterback must recall what “55 Slant Right”
means in terms of the patterns the receivers will run. At the line of
scrimmage, he must evaluate the set-up of the defense and, as the play
unfolds, determine if the intended receiver is coming open. Once the
decision to throw has been made, the quarterback must execute the pass
precisely to get it within the receiver’s reach. Knowledge, decision, and
execution - these three components are present in most tasks, although
tasks vary widely as to which component dominates.

This analysis applies to the military as well. Soldiers rely on three
abilities as they attempt to perform their military tasks: (1) ability to
retrieve from memory previously-learned knowledge (job-related facts,
rules, terminology, order of steps to be performed in a procedure, etc.);
(2) ability to combine incoming information, evaluate a situation, and
decide among alternative courses of action; and (3) ability to execute the
chosen action or procedural step in a sufficiently skilled manner.

In most military tasks, the first ability — knowledge retrieval —
predominates. In one sense, this is true because soldiers must call to
mind a number of job-related terms and rules as they carry out any task.
But it is also true in the sense that there is a separate class of tasks that
depend on information recall. These tasks are generally referred to as
procedural tasks, because the crucial recall required is memory for the
steps to be performed in a given procedure. The second ability —

“Knowledge,

decision, and
execution -
these three
components

are present in

most tasks...”


“Research has

consistently
found low
error rates
when high-
quality job or
memory aids

are used...”

U.S. Army Research Institute

Research has consistently found low error rates when high-quality job or
memory aids are used to perform tasks. An Army study of Chaparral
missile system crews, for example, found no decline in performance on
six tasks up to four months after initial training. Soldiers performed each
task, as intended, with easy access to their technical manuals.*'

Time Limits and Stress

Some tasks have time limits that must be met for some or all task steps.
Examples are assembling an M60 machine gun, donning a gas mask, and
performing CPR. Time limits have a direct effect on retention of
proficiency by defining what it means to say a soldier is “sharp” on a
particular task. One effect of the passage of time without practice is a
general slowing of both physical and mental performance; “rusty”
soldiers may fail to meet a strict time limit, even when they know what
needs to be done. However, only time limits that are difficult to meet
have the effect of making a task hard to remember; such strict time limits
also add to the stress experienced by the soldier being tested on a task,
and the stress may make it hard for the soldier to concentrate on the
important aspects of the task. In fact, time limits help mimic the
situations in which some tasks must be done. It is mostly the set of tasks
soldiers must learn to perform well under stress — those related to
combat and safety — that include established time limits.

Predicting Military Task Retention

All this has been taken into account in the development of an ARI
research product. In 1981, under the sponsorship of the Army Training
Board, ARI undertook a 3-year effort to organize and integrate many of
the retention research findings just described into an instrument for
predicting how rapidly individual procedural tasks are forgotten.** The
result of this effort is the User’s Manual for Predicting Military Task
Retention®, also called the User’s Decision Aid or UDA by current users.
The UDA was designed to guide the user through a process of
numerically rating an individual task on the factors just discussed.

The output is a single score that predicts the decline in performance
among soldiers who start out 100% proficient. It identifies a curve that
gives the percentage of soldiers in a unit who will be able to perform the
task correctly after a given interval of no practice. Training managers can
use the UDA to answer questions such as:

How quickly will a particular task be forgotten?

Among several tasks, which is most likely to be forgotten or
remembered after a given interval?

When should reacquisition training on a particular task be
conducted to keep group performance from falling below an
acceptable level?

Scoeonao Z z roa z sce



U.S. Army Research Institute

disassemble the M240 coaxial machine-gun, for example, the soldier
must remember the names, functions, and locations of the buffer
assembly, the bolt assembly, the driving rod and spring, and the trigger
assembly. The soldier must also remember, for example, to remove the
driving rod and spring before removing the bolt assembly.

Such information is sometimes referred to as school knowledge. Studies
of memory for knowledge learned in school have sometimes found
remarkable resistance to forgetting for years after learning.'?In fact, some
kinds of school knowledge — for example, vocabulary from high school
Spanish — apparently stay with a person for a lifetime.'? However, a
distinction based on the way performance is measured can be crucial; the
amount of forgetting found depends on whether the memory test requires
recognition or recall.

Recognition memory involves choosing the correct response from a
number of alternatives and is usually tested with multiple-choice,
matching, or true-false test items. Recall memory requires the learner to
produce information without being presented with alternatives and is
usually tested with short answer, fill-in, or essay test items. In general,
because of the cues provided by the alternatives, recognition memory is
superior to recall memory. Figure 3 summarizes the research findings
from more than 40 studies® of recognition and recall memory for
retention periods up to 52 weeks.



TRAINER'S GUIDE FOR REFRESHER TRAINING
-- OPERATION JOINT ENDEAVOR --

RANKING OF TASK RETENTION
(Task ranked #1 Is hardest to remember.)

% Go = percent of soldiers predicted to pertorm the task
at ‘Go’ level after two months of non-use

Bank Task % Go. Bank ___Task % Go.
#1 - Extraction from Minefield 0% #14 - Living in the Cold 62 % (48%)
2- React to Civilian on Battlefield 8% 15 - \dentify/Detect Trip Wires 68%
3- React to Sniper 9% 17 - Driving Postcheck 71% (44%)
4- Prevent Shock 18% 17 - Working In the Cold 71%
5- Carbon Monoxide Inhalation 28 % 17 Identify/Detect Booby Traps. 71%
6- Apply Tourniquet 29% 19 - Sleeping in the Cold 73%
7.5 - React to Indirect Fire. 30% 20 - Recognize/ React to UXO 75%
7.5 - Winter Driving 30% Mine Detection 76%
9- Vehicle Search WG .5 - Locate a Mine by Probing 76%
10- Negotiation 36 % 23 - Driving Precheck 89 % (62%)
41- Rules of Engagement 42% (27%) | 24- Personal Search 90 % (62%)
12- React to Media 54% 25 - React to Mines 96 % (68%)
13~- V Corps Convoy Mine Strike Drill 56 % 26 - Field Dressing/Pressure Dressing 98 %
27 ~ indications of Mines/Booby Traps 99% (84%)
NOTE: Tasks with two ‘Go! percentages have job alds; percentages in parentheses apply when job aids are not avallable,

See the reverse side for factors to consider when scheduling these tasks for refresher training.

Figure 10. Pocket job aid for
optimizing refresher training.

U.S. Army Research Institute

roe gn ”

This can be accomplished by increasing the number or length of training
sessions or the number of practice repetitions.*” We mentioned above that
amount of original learning or degree of overlearning that a soldier
experiences during initial training is the best predictor of how good that
soldier’s skill retention will be.

Test During Training

Another technique for improving retention is to employ frequent testing
during training. In a series of studies involving motor skills, ART
researchers found that repeated testing trials resulted in superior
retention.”

21



Us. Army Research Insitele
Special Report 39

hily 1999

Ratention of
Military



Retention of Military Knowledge and Skills

Research has shown that memory for continuous (perceptual-motor)
skills is different from memory for discrete (procedural) skills.'° As said
above, skill at discrete, knowledge-dependent procedural tasks may show
considerable decay in just a few weeks or months. However, studies
dating back to the 1950s have found high long-term retention of
continuous skills. Perceptual-motor tasks, such as typing, aircraft flight
control, target tracking, marksmanship, or the proverbial bikeriding,
show virtually no skill loss for periods as long as two years without
practice." In a study of helicopter pilots in the IRR", for example, even
airmen who had not flown for many years retained flying skills well and
were able to reacquire any lost skill quickly.

Figure 4 shows data on memory for a typical example of one perceptual-
motor task and one procedural task. These examples are taken from a
study of skill retention conducted by ARI during the partial mobilization
of the IRR during Operation Desert Storm.'® Memory for perceptual-
motor skills, represented by the marksmanship scores at TOW gunnery,
shows much the same resistance to decay as was seen (Figure 3) in
recognition memory for school knowledge. Discrete, procedural skill,
however, may be forgotten much more rapidly; in Figure 4, scores on a
test of memory for several quartermaster procedural tasks are below the
“Go” level (80%) for all retention periods.

Figure 4. Typical memory for
perceptual-motor (continuous)
and procedural (discrete) tasks.

TOW Gunnery Score

er ceptiat mot Task

Procedural Task

GO

800 5 100
von *——__, 20 + al
GO g 6
600 }— g
3 40
500 - 20
400 T 1 oO

2toS 6 tod 10 to 13 2to5

Time out of service (Months)

6 too
Time out of service (Months)

10 to 13

Many procedural tasks show this quick decline. It has been found, for
example, that only 20% of civilians trained on the first aid task of giving
cardio-pulmonary resuscitation (CPR) are proficient six months later.”°
There are also exceptions, however. A study of Army basic combat skills
showed an average loss of as little as 5 percent after 6 weeks for some
tasks (e.g., first aid for shock) and as great as 52 percent for others (¢.g.,
clearing an M16 rifle).”' Figure 5 shows the set of curves that
performance would be expected to follow. Each curve represents a
different procedural task. Note that some of these tasks, those



U.S, Army Research Institute

Memory for Execution Skills

Tasks in all MOSs have an execution or performance component,
although this aspect may be trivial when the performance involves
behaviors practiced for years, in some cases for a lifetime.
Administrative Specialists, for example, may complete many of their
clerical tasks by simply filling out a form with a pencil or on a computer
screen. Some MOSs, however, entail skilled performance in using tools
or operating complex equipment. For example, one of the task steps in
boresighting the direct fire telescope on an M198 howitzer involves
rotating the M32 periscope elevation and deflection boresight knobs until
the aiming cross is on the upper left-hand corner of the target. This
precise rotation requires considerable manual dexterity.

Continuous Execution versus Discrete Procedure

Memory researchers classify such performance skills as either continuous
or discrete. Continuous skills involve movements or steps that do not
have distinct beginnings or endings; examples include driving a vehicle,
keeping a weapon sight on a moving target, and flying an aircraft. As
noted above, these are also called perceptual-motor tasks. Discrete skills,
on the other hand, are needed for tasks with definite beginnings and
endings — for example, starting up a radio communications system,
disassembling a carburetor, or performing a vehicle safety check. These
can be recognized as what we earlier called procedural tasks.

<= = sao = SEES



Report DocumeENTATION PAGE On te rss

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1. AGENCY USE ONLY (Leave Blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED
July 1999. Final - Oct 1998 - Mar 1999

5. FUNDING NUMBERS:

4, TITLE AND SUBTITLE

Stayi 2 ion of Mili 1 kills.
‘taying Sharp: Retention of Military Knowledge and Skills. Program Element Number: 62785

Project Number: A790

© AUTHORS) ,
Robert A. Wisher, U.S. Army Research Institute; Task Number: 2233
Work Unit Number: C06

Mark A. Sabol,U.S. Army Research Institute; John Ellis, K. Ellis Human
Resources Services and Consulting

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER
Human Resources Research Organization
66 Canal Center Plaza, Suite 400
Alexandria, VA 22314-1591

9, SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY REPORT NUMBER,

U.S. Army Research Institute for the Behavioral and Social Sciences
ATTN: TAPC-ARL-II Special Report 39
5001 Eisenhower Avenue, Alexandria, VA 22333-5600
Alexandria, VA 22333-5600

11 SUPPLEMENTARY NOTES

12a, DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

Approved for public release; distribution is unlimited.

18, ABSTRACT (Maximum 200 words):

This report reviews what is known about forgetting as it applies to military tasks. It includes research conducted by
the Army Research Institute as well as related work performed by the Air Force and Navy and leading academic
institutions. The report distinguishes the memory for knowledge and skill related to procedural tasks, cognitive
tasks, and perceptual-motor tasks. Memory for task knowledge has been demonstrated to be quite good. Memory
for cognitive skills has been demonstrated to be quite good. Memory for psychomotor skills varies, depending on
whether the task is continuous, such as riding a bicycle, or discrete, such as executing the separate performance steps
involved in disassembling a rifle. Throughout the report, figures depict the relative sustainment or decay of a skill as
reported in the research literature. A final section concerns the factors that influence the reacquisition of a skill after
extended periods of nonuse, as might occur during a mobilization.

14, SUBJECT TERMS 15. NUMBER OF PAGES.
training, learning, skill acquisition, skill retention, knowledge, refresher training, 2

memot
y 16. PRICE CODE

18. SECURITY CLASSIFICATION OF | 19. SECURITY CLASSIFICATION OF | 20. LIMITATION OF ABSTRACT
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Prescribed by ANSI Std 239-18 298-102

17. SECURITY CLASSIFICATION OF REPORT
Unclassified

NSN 7540-01-280-5500



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39.

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U.S. Army Research Institute

Shields, J., Joyce, R., & Van Wert, J. (1979). Chaparral skill retention (Research Report 1205, ADA069945). Alexandria, VA: U. S. Army
Research Institute for the Behavioral and Social Sciences.

Ratke, P., & Shettel, H. (July 1985). Training program for predicting military task retention: Evaluation report (Technical Report 683).
Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Rose, A., Czarnolewski, M., Gragg, F., Austin, S., & Ford, P. (1985). Acquisition and retention of soldiering skills (Final Report 671).
Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Macpherson, D., Patterson, C., & Mirabella, A. (1989). Application of ARI Skill Retention Model to Wheel Vehicle Maintenance Tasks
(Research Report 1538). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Sabol, M., Chapell, L., & Meiers, C. (1990). Predicted decay of mobile subscriber equipment operator skills (Research Product 90-11).
Alexandria, VA: U. S. Army Rescarch Institute for the Behavioral and Social Sciences.

Kem, R., Wisher, R., Sabol, M., & Farr, B. (1993). Reacquisition of skill by combat engineers mobilized from the Individual Ready
Reserve (Research Report 1667). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Sabol, M. (February 1998). PREMO: Accelerating mobilized soldiers’ reacquisition of skills. In 7997 In-house Researchers’ Colloquium
(Special Report 35). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Wisher, R., Sabol, M., & Ozkaptan, H. (1996). Retention of “peace support operations” tasks during Bosnia deployment: A basis for
refresher training (Special Report). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Sanders, W. (In press). Digital procedural skills retention for selected MIA2 Tank Inter-Vehicular Information System (IVIS) Tasks. ART
Technical Report.

Krueger, W. (1929). The effects of overleamning on retention. Journal of Experimental Psychology, 12, 71-78.

Hagman, J. (1980a). Effects of training task repetition on retention and transfer of maintenance skill (Research Report 1271). Alexan-
dria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Goldberg, S., Drillings, M., & Dressel, J. (1981). Mastery training: Effects on skill retention (Technical Report 513). Alexandria, VA: U.
S. Army Research Institute for the Behavioral and Social Sciences.

Earles, J., & Ree, M. (1992). The predictive validity of the ASVAB for training grades. Educational and Psychological Measurement, 52
(3), 721-725.

McHenry, J., Hough, L., Toquam, J., Hanson, M., & Ashworth, S. (1990). Project A validity results: The relationship between predictor
and criterion domains. Personnel Psychology, 43(2), 335-354.

Palmer, R., & Buckalew, L. (November 1988). SINCGARS Operator Performance Decay (Research Report 1501). Alexandria, VA: U. S.
Army Research Institute for the Behavioral and Social Sciences.

Wisher, R. (1991). Desert Storm mobilization: Skill decay and attitudes in the IRR (ARI Newsletter, 7, 1-4). Alexandria, VA: U. S. Army
Research Institute for the Behavioral and Social Sciences.

Sabol, M., Maisano, R., & Wisher, R. (August 1996). Predictors of retention and reacquisition of military job knowledge. Paper
presented at the 104" annual meeting of the American Psychological Association, Toronto, Ontario.

Rigg, K. (May 1983). Optimization of skill retention in the U. 8. Army through initial training analysis and design: Prototype skill
sustainment guide (Technical Report MGA-5181-PRO-ANNEX). Fort Eustis, VA: U. S. Army Training Board.

Hagman, J. (1981). Testing during training: Why does it enhance long-term motor task retention? (Technical Report 535). Alexandria,
VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Hagman, J. (1980d). Effects of training schedule and equipment variety on retention and transfer of maintenance skills (Research Report
1309). Alexandria, VA: U. S. Army Research Institute for the Behavioral and Social Sciences.

Sturges, P., Ellis, J., & Wulfeck, W. (1981). Effects of performance-oriented text upon long term retention of factual material (Technical
Report NPRDC TR 81-22). San Diego: Navy Personnel Research and Development Center.

Semb, G., Elis, J., & Araujo, J. (1993). Long term retention of knowledge learned in school. Journal of Educational Psychology, 85, 305-
316.

Ellis, J., Semb, G., & Cole, B. (1998). Very long term memory for information taught in school. Journal of Contemporary Educational
Psychology, 23, 419-433.

Sabol, M., Kem, R., Eigelkind, M., & DiMarino, C. (November 1993). Effects of rapid training on soldiers’ occupational knowledge.
Proceedings of the 35"" Annual Conference of the Military Testing Association. Williamsburg, VA.

Sabol, M. (June 1998). Accelerating mobilized soldiers’ reacquisition of skills. Proceedings of the 21% Army Science Conference.
Norfolk, VA.

27



Retention of Military Knowledge and Skills

Memory for Decision Skills

Many military tasks involve cognitive
components such as problem solving,
judgment, and analysis leading to a decision.
For example, in land navigation soldiers
must interpret topographical maps to
identify symbols with terrain features on the
ground. And any troubleshooting task will
require soldiers to reason their way to the
diagnosis of a particular fault in the
equipment.

Research on memory for cognitive tasks
shows a moderate rate of decay; forgetting
occurs but is relatively small for up to a year
after learning. Figure 2 summarizes more than 20 studies’, including two
studies of military tasks. One tested anti-submarine warfare trainees on
the application of oceanography principles immediately and four weeks
after training and observed a 21% drop in scores.'° Another measured
basic electricity problem solving and found a 16% loss in skill after 8
weeks.!!

100 -
Anan
£
Zz 60
g
=
8 40
5
: 20

te) r T 1
1 to 13 14 to 26 >26
Retention Interval (weeks)
Memory for Job Knowledge

All military tasks have a knowledge component, facts and ideas that the
soldier must remember in order to perform successfully; this information
may be as basic as the definitions of task-relevant terms or as complex as
the order in which the task’s procedural steps should be performed. To

Figure 2. Average of 20
cognitive tasks.



18

Aptitude

Aptitude for learning is usually measured
by a paper-and-pencil test and is predic-
tive of an individual’s success in a school
setting. Military enlisted personnel vary
widely in such aptitude as measured by
the Armed Services Vocational Aptitude
Battery (ASVAB). Training and job
assignments are based in part on ASVAB
scores or, rather, on one of the composite
scores obtained by adding together an
individual’s scores on several subtests.
The composite score most useful as a
general predictor of an enlistee’s ability
to benefit from original training is
known as the Armed Forces Qualification Test (AFQT). This is a combi-
nation of subtest scores measuring verbal and numerical aptitudes. The
power of AFQT scores and other ASVAB composites to predict training
success (and, therefore, level of original learning) is well established, for
example, by work at the Air Force’s Armstrong Laboratory.’ Research
for ARI’s Army Selection and Classification Project (Project A) showed
that aptitude measures also predict later job performance; while measures
of vocational interest and spatial and perceptual-motor abilities were
important predictors of such measures as General Soldiering Proficiency,
measures of aptitude for learning were the best predictors.

However, the influence of aptitude on skill retention is not so clear. On
the one hand, several studies have shown that, although high-aptitude
trainees learn more than low-aptitude trainees do, their rate of forgetting
is sometimes the same. For example, in an Army study of 13 basic
training tasks (see Figure 9), high-aptitude soldiers out-performed low-
aptitude soldiers both at the end of basic training and six weeks later; but
the performance differences between the high and low aptitude soldiers
on the six-week test were the same as at the end of basic training.” Ina
similar ARI study of knowledge and skill among radio operators**,
although ASVAB soldiers’ aptitude scores explained about 25% of the
variability in their performance both immediately after training and three
weeks later, an individual’s aptitude score did not predict how much
one’s performance would decay over those three weeks.

On the other hand, higher-aptitude soldiers are more likely than lower-
aptitude soldiers to reach the level where overlearning — practice
beyond the point of correct performance — can occur, if the same
amount of training time is available to all. Since, as noted above, those
who overlearn a task will show less memory decay over periods without
practice, higher-aptitude soldiers will show greater skill retention in these
situations.



The Reacquisition Curve

Retention of Military Knowledge and Skills. e=========== =

Finally, in addition to assessing skill decay and exploring retraining

strategies, these same
researchers combined
data from several of their
IRR studies, in order to
document, at least roughly,
how much time mobilized
soldiers need to reacquire
skills. Figure 11 displays
two data points from each
of three studies, one for
retention and one for
retraining. That is, each
study contributed, for its
set of procedural tasks, the
performance of soldiers
after zero retraining (the
retention measure) and
their performance after the
specific amount of
retraining time (averaged
across tasks) used in that

study. A final point is added to the figure to represent the obvious
expectation that, if soldiers were provided with retraining that lasted as
long as their original training, all would become proficient.

100

feed
Ss
L

faz
So
oe

&

20 |

% of Soldiers Getting "Go"

40 60 80 100

% of Original Training Time

The performance measure in Figure 11 is the percentage of soldiers who
performed the tasks successfully. The time available for retraining is
expressed as a percentage of the original amount of time required in the
Amy school to train each task, according to the official Program of
Instruction (POI). For each study, this value was averaged across all
tasks. Note that this POI time is an alternative method of gathering a set
of data similar to the “acquisition performance” investigated by the
developers of the UDA and found to be a good predictor of retention.
Both provide a general measure of how difficult tasks are to train,
although in this case the measure is averaged over the dozen or so tasks
included in each rapid train-up.

The fact that a smooth curve was obtained when data from several
different studies were combined in this way supported the idea that a
general relationship was being revealed. That is, Figure 11 was
considered a first approximation of the relationship between how long it
takes to train a task originally and how much time is needed to retrain
soldiers to the point where any desired percentage of soldiers will be
back up to speed on the task. It is assumed to apply to any situations
(combinations of tasks and retention intervals) that would yield the same

Figure 11.
The reacquisition curve.


U.S. Army Research Institute

TABLE OF CoNnTENTS

How Much is Remembered for How Long?........cseesesssseseeeeeeee 2

The Different Kinds of Skills 2
Memory for Decision Skills 4
Memory for Job Knowledge 4
Memory for Execution Skills occ eeeseeseseeseeseereetesesteneeeeee 7

Continuous Execution versus Discrete Procedure.......... 7

Factors Affecting Procedural Skill Retention

Task Factors
Task Complexity 0.0... scecsessesessseesseeesrereesssessesecerereseneens 10
Task Demands ........csccccssessessssesssesssssssessssesseesseeseeesseeneees 12
Testing Factors
Job and Memory Aids
Time Limits and Stress .........cscscessssessesscesssseeseseeseeeeenenee 15

Predicting Military Task Retention 2.0.0.0... eeseseeeseseeeeeeees 15

Individual Factors...
Original Learning.
Aptitude

Improving Skill Retention
Optimize the Schedule of Refresher Training
Maximize Original Learning
Test During Training .
Provide Spaced Practice .........secsessssssseseeseseeseseeeteneeeeseeneseenees 22
Use Task-oriented Training .
Encourage Peer Tutoring .

Skill Reacquisition 0.0.0... cesses eeesesesseseseseseensseseseeessensseesseseseeees 23
The Reacquisition CUrve ......s.sssesssesseeseeresseesesseessesseeseeseeeee 24
Conclusions

References ......scesessessesesseseesessssessssessesesssesesseseesssceeescerenreneseenesnees 26



Figure 7. Task difficulty affected by
adding task steps.

U.S. Army Research Institute

100
*o
P 80+
=
2 60
(o)
§
3 40;
8
% 207
ae

0 T T T
0 5 10 15 20
# of Task Steps

basic training. All the soldiers, having demonstrated their ability to
perform the tasks at the end of training, were then re-tested at periodic
intervals. Figure 7 shows performance for four of the tasks 12 months
after training. The tasks and number of steps are: (1) report enemy
information, 3 steps; (2) load and fire M203 grenade launcher, 9 steps;
(3) perform cardiopulmonary resuscitation, 14 steps; and (4) don gas
mask, 15 steps.”

Note that the drop in performance from the 3 step task to the 9 step task
is only 18%, while the drop as steps increase from 9 to 14 is 31%; and
the addition of just one step from the 14 to 15 step tasks causes another
21% drop. As the number of task steps increases, the performance
decrements become more severe. This is an example of the limitation on
human memory known to psychologists as “the magic number 7 plus or
minus 2””’; when one is asked to remember more than 9 items, the mind
is likely to become a blur. This is especially true if the items must be
remembered in order.

‘STEPS DONE IN SEQUENCE. In some military tasks, such as “Identify Terrain
Features on a Map,” the steps can be performed in any sequence. Other
tasks, such as “Splint a Fracture,” have only one correct sequence. For a
third type of task, for example, “Perform Operator Maintenance on an
MI16A\ Rifle,” some steps must be performed in sequence and others
can be performed in any order.

Psychologists have long known that memory for order information is
especially slippery. Army research on memory for sequence has
confirmed the expectation that tasks one can perform in any sequence are
easiest to remember. Somewhat surprisingly, however, it turns out to be
easier to remember a specific sequence for all steps than for only some
of the steps”; that is, the hardest task to remember is one that has a fixed
sequence imbedded in other interchangeable steps.



U.S. Army Research Institute

Failure to recall just one such crucial fact
may make some tasks impossible.

Coenmive Skit Demanps. As discussed above
(see Figure 2), memory for cognitive skills
is fairly stable for periods as long as a year
after learning. However, cognitive skills do
suffer some decay;” they are more likely to
be forgotten than simple motor skills, such
as saluting or marching. Tasks with several
cognitive elements, those that require
multiple steps of judgment or decision-
making, will suffer more degradation over
time than tasks with just one or two such
steps. Further, some cognitive components
are more complex than others; tasks that
demand processing of large amounts of
technical information or rapid decision
making (e.g., setting priorities for targets)
may be blocked by the breakdown
(overload, burnout) of one complex
cognitive skill.

Execution Demanos. Almost all tasks involve
some degree of motor control of finger, hand,
and arm movements. It turns out that tasks
which require an intermediate degree of motor
control are remembered best; these are usually
continuous execution tasks, such as typing or
flying a helicopter. As discussed in the section
on execution skills, memory for these continuous tasks remains high for long
periods. On the other hand, some discrete procedural tasks that require a high
degree of motor control may also be done rarely, such as the occasional
repair of delicate equipment. In such cases, the unpracticed performance is
likely to be poor. Whereas the well-practiced hand is steady, the anxiety
caused by knowing that one’s skills are dull may be enough to interfere with
completing the task. Surprisingly, however, ARI researchers® found that
tasks with only a minor requirement for fine motor control, such a
hammering a nail, or those that involve sheer strength, are more vulnerable to
decay than are tasks that require moderate precision and accuracy. Perhaps
the concentration needed for that precision aids in the formation of solid
overall task memories.

Testing Factors

The following two factors relate to the situation under which the soldier’s
memory for a particular task is tested. To insure that the resulting
measure is a valid one, the same conditions should hold during training
sessions.



Cover Photograph:
Military Photographer of the Year Winner 1997

DoD Photo by: SSG Justin D. Pyle

STAYING SHARP:
RETENTION OF MILITARY
KNOWLEDGE AND SKILLS

Robert A. Wisher
Mark A. Sabol
U.S. Army Research Institute

John A. Ellis
K. Ellis Human Resources Services and Consulting

-_~.
G) ARI Speciat Report 39
JuLy 1999

CTED 4
pric QUALITY INSPE!



22

Retention of Military Knowledge and Skills

Provide Spaced Practice

A further means of improving retention is to use spaced or “distributed”
repetitions during practice sessions. Substantial laboratory research
shows that inserting a time interval between repetitions of a task during
learning increases retention. Army researchers have extended this finding
to Army tasks. In a maintenance task study, one group of fuel and
electrical repairers performed three task repetitions in succession (massed
repetitions), while another group performed the same task every other
day (spaced repetitions). When both groups were tested two weeks later,
the massed group took 51 percent longer to complete the task and
committed 40 percent more errors than the spaced group.*°

Use Task-oriented Training

Task-oriented training involves using the context of the task to teach the
factual knowledge and cognitive skills required for task performance. It
is often contrasted with topic-oriented training, in which information is
taught more abstractly, without reference to job applications. For
example, in military courses on the principles of basic electricity and
electronics, the instruction rarely mentions how and where concepts and
principles such as Ohm’s or Coulomb’s Law will be applied when
trainees begin their job assignments. Researchers have shown that task-
oriented training is effective at producing both high original learning and
good retention. For example, a Navy-sponsored study*! compared task-
oriented and topic-oriented instruction on metal fasteners (e.g., bolts,
screws, nuts) in a basic mechanics course. Trainees in both the topic- and
task-oriented training conditions were taught to a 90% criterion; after 6
months, the task-oriented trainees recalled significantly more than did the
topic-oriented trainees.

Encourage Peer Tutoring

Finally, a large number of research studies have shown that peer tutoring,
having students teach each other, enhances original learning. But two
studies by Navy researchers also showed the effects of peer tutoring on
retention. In the first study, performance for both the peer tutors and the
students who received the tutoring was near 100% at the end of initial
learning. Six months later, however, the peer tutors remembered
significantly more than did the students they tutored.*? The second study
examined the effects of tutoring over longer retention intervals. Tutors
were found to retain more than non-tutors did for periods as long as eight
years. This is apparently an example of the old saying, “To teach is to
learn twice.”



ForEWORD

The U.S. Army Research Institute for the Behavioral and Social
Sciences (ARI) has been investigating soldiers’ retention of skills
and knowledge learned during training. How well a soldier remem-
bers what was learned in training influences how well a soldier can
later perform a task and determines the frequency with which re-
training needs to occur. Understanding the nature of skill retention
thus has important implications for both Army training and person-
nel policy.

The research reported here summarizes over 25 years of work on the
topic of skill retention. The report emphasizes research performed
by ARI, but also includes relevant research by other military and
academic laboratories. Products from ARI research include a model
for predicting skill retention, endorsed by TRADOC and applied
numerous times, most recently to the ‘peace support operations’
tasks trained to troops deploying to Bosnia. This research has also
led to personnel policy changes, such as increasing the window
(from 12 months to 24 months following active duty) for the initial
recall of soldiers from the Individual Ready Reserve in the event of
a mobilization. We plan to continue research on skill retention
issues, focusing on the digital skills required for the decentralized,
fluid, fast-paced operations of the future.

EDGAR M. JOHNSON
Director



“Army

trainers and
planners can
predict how
rapidly
individual
procedural
tasks will be
forgotten...
[and so]
optimize the
schedule of
refresher

training.”

U.S. Army Research Institute

retention performance as found in these studies, an average 38% of the
soldiers remembering enough to receive a “Go” with no additional
training.

The figure can be used by trainers to plan how much retraining time is
needed in such situations to reach a preset level of proficiency, say 90%.
It suggests, for example, that 35% of original training time is needed to
retrain soldiers from a 38% level of proficiency to the point where 90%
of them will perform at a “Go” level. Application would be as follows: If
it has been determined, by long experience, that 10 hours of school time
is needed to successfully train a particular task, then about 3 1/2 hours
should be devoted to retraining soldiers, 100% of whom once knew the
task but 62% of whom have now forgotten it. These 3 1/2 hours of
retraining would bring the group back to 90% proficiency; according to
Figure 11, providing more than 3 1/2 hours of retraining would not
produce much additional benefit. This figure, then, gives a rough
recommendation for how much retraining should be scheduled for this
task. More research is needed to describe the similar curves that should
apply when tasks have undergone different degrees of skill decay.

CoNcLUsIONS

In the post-Cold War world, the option to rapidly mobilize and deploy
highly skilled personnel is essential. But the success of this option for the
Army depends upon soldiers’ retention of the military knowledge and
skills they once learned or on their capacity for rapid re-learning.

ARI has been studying the retention of knowledge and skills for three
decades. This research has resulted in a detailed understanding of the
patterns of forgetting that occur in job knowledge and in cognitive and
perceptual-motor skills. We have identified the factors that affect
forgetting of procedural skills and developed the User’s Manual for
Predicting Military Task Retention. With this manual, Army trainers and
planners can predict how rapidly individual procedural tasks will be
forgotten; this information enables them to optimize the scheduling of
refresher training.

Researchers have also identified instructional strategies, such as provid-
ing spaced practice and peer tutoring, that Army trainers can use to
improve soldiers’ retention of what they were originally taught and speed
their re-sharpening of skills grown dull. Army planners can now identify
those individuals least likely to suffer major skill decay while in the IRR.
They can even make rough predictions of the time needed to reacquire
proficiency on different tasks. All these are potential improvements in the
retraining portion of any future mobilization.

The Army Research Institute continues to take a systematic, scientific
approach to training. Our research products, serving to upgrade both
sustainment and retraining of skills, demonstrate the value of this ap-
proach to the readiness of the Army.

25



Figure 5. Theoretical set of
curves for the decay of
skill at different procedural
tasks.

‘h of Soldiers Getting "Go"

Skill Retention Curves.

Weeks Without Practice

Figure 6. Mobilized IRR soldiers’
performance on procedural tasks
before retraining.

represented by the upper curves, suffer so little forgetting that they show
fairly constant performance, month to month. Other tasks, those on the
lower curves, show constant performance after the first few months,
because most of the decay they will suffer has already occurred. But there
are many tasks in between these two extremes.

The variability of real-life results for discrete procedural skills is shown
in Figure 6. The data are from an ARI study of skill retention by 197
volunteers from the IRR.” After being called back to active duty for a
mobilization exercise, these soldiers were given hands-on tests of their
memory for common soldiering tasks. All these soldiers, who had been
away from active

duty for an average
36 months,

Evaluate casuaty

sn -_ performed all the

Pravent shock

tasks. The percent of

Appi feld cessing

Wear Me17 mask

Maintain M1842 rite
Maintain M17 mask

Idenity terrain fakes
Determine ground location
Preform functon check M16. a
Correct matunctions on M16:
Determine gid coordinates
React lo chem/bio hazard

Decen skivequipment

soldiers able to
perform at a “Go”
level ranged across
tasks from 73% (for
Evaluate a Casualty)
to 17% (for

Decontaminate Skin
| and Equipment).

This variability
among discrete
procedural tasks is
important, because,
as mentioned, such
procedural tasks

' 1 1 ' ' 1 '
30 40 50 60 70 co) 90 100



12

Retention of Military Knowledge and Skills = «===== ===

Bui.t-IN FEEDBACK. Some tasks provide feedback for some or all of the task
steps, indicating when a step has been performed correctly. Examples of
tasks with feedback are disassembly tasks where removing one part
reveals the next part to be tackled or tasks where performing a step
causes observable results, such as a panel lighting up or a warning buzzer
sounding. Feedback makes task steps less likely to be forgotten.

For sequential tasks, feedback may be especially beneficial when it acts
as a cue for remembering the next step to be performed. In the ARI
retention study of basic training tasks, the task steps that were forgotten
most frequently were those that were not cued by the sequence of steps
or by the equipment.”° For example, when disassembling an M16 rifle,
soldiers frequently forgot the first step, the safety step of clearing the
weapon.

Task Demands

The task components of knowledge, decision, and execution, used earlier
to classify tasks in general, return here as aspects of tasks within the
procedural class. That is, procedural tasks can vary greatly in these
aspects, as described below, and this variation is reflected in how well
soldiers can retain memory for the tasks.

Knowtepce Demanos. Memory for tasks that involve recall of terms,
definitions, names, locations, and other facts (see Figure 3) is directly
affected by the number and complexity of facts that must be
remembered. The findings for number of facts are similar to the findings
for number of task steps described above. Tasks that do not require
soldiers to recall any auxiliary
facts, or only a few, are
remembered best; tasks that
require 4 to 8 such items are
remembered well; but tasks that
require recall of more than 8
pieces of information suffer rapid
decay without constant practice.

A related consideration is how
hard these auxiliary facts are to
remember. Some tasks require
concurrent recall of only a few
items, but those items, by their
nature, easily slip the mind. For
example, call signs and radio
frequencies are notoriously
forgettable, because they are
assigned at random for exactly the
purpose of being non-predictable.