ARL-TR-2835 SEPTEMBER 2002

The Effects of Information Availability and

Information Management on the Performance

of Dismounted Military Teams

Monica M. Glumm

Ramakrishna Pillalamarri

Frederick S. Brundick

Approved for public release; distribution is unlimited.

ARMY RESEARCH LABORATORY
NOTICES

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The findings in this report are not to be construed as an official

Department of the Army position unless so designated by other

authorized documents.

Citation of manufacturers’ or trade names does not constitute an official

endorsement or approval of the use thereof.

DESTRUCTION NOTICE Destroy this report when it is no longer

needed. Do not return it to the originator.
i

Army Research Laboratory

Aberdeen Proving Ground, MD 21005-5425

______________________________________________________________________________

ARL-TR-2835 September 2002

______________________________________________________________________________

The Effects of Information Availability and Information

Management on the Performance of Dismounted Military

Teams

Monica M. Glumm

Ramakrishna Pillalamarri

Human Research & Engineering Directorate

Frederick S. Brundick

Computational and Information Sciences Directorate

______________________________________________________________________________

Approved for public release; distribution is unlimited.

______________________________________________________________________________
ii

ACKNOWLEDGMENTS

The authors wish to express their appreciation to all those within and outside the U.S. Army

Research Laboratory (ARL) who shared their time and expertise in the planning and execution of

this field investigation.

First and foremost, we would like to thank our Marine Corps participants for their interest,

patience, and exceptional performance.

We would also like to express our appreciation to the 42 infantry soldiers who participated in an

earlier survey that helped to identify measures of mission success and tactical information

requirements. Special thanks to Don Parks and our other colleagues from ARL’s Human Research

and Engineering Directorate (HRED) field element at Ft. Benning Georgia, who assisted in the

development and administration of the survey. Thanks also to Teresa Branscome of the Cognitive

Sciences Branch at HRED, ARL, who supported us in the analysis of these data.

Many thanks to Cadet Brian Stone of the U.S. Military Academy at West Point who participated

in all facets of the field investigation including programming, equipment troubleshooting and

repair, participant training, “lane walking,” and data collection.

Thanks to Dr. Bill Marshak of Sytronics, Inc., for the DASHER systems and his technical

support throughout the planning and testing phases of this study.

We also wish to thank the following members of the Simulations Systems Branch of ARL’s

HRED for their outstanding support:

• Dennis Hash and Nicky Keenan for fabricating and integrating backpacks with the

DASHER system and power supply, developing three-dimensional targets, and preparing the

cross-country training and test courses;

• D.J. Brown and Tom Hoerr for metal work in the integration of system components;

• Dave Kuhn for electronics support in the integration of helmets, earphones, and audio

amplifiers;

• Mike Kosinski for the scaling and fabrication of military protractors and for developing

annotated paper maps; and

• Dave Ostrowski for facility and operations support.

Thanks to our other friends at ARL, including Debra Patton (Cognitive Sciences Branch of

HRED) and Tim Mermagen (Visual and Auditory Processes Branch of HRED) for developing the

auditory recordings and files.

Finally, thanks to the other members of our research team, including Bill Harper, Sam Ortega,

Dave Scribner, and Jack Waugh, for their assistance as “lane walkers” and data collectors

throughout the training and testing phases of the investigation, and to SFC David Stevens for his

assistance in the development and delivery of the operations orders and support during the

training phase of the study.
iii

Contents

1. Background ............................................. 1

2. Objectives .............................................. 4

3. Method ................................................ 4

3.1 Participants............................................ 4

3.2 Apparatus............................................. 4

3.2.1 Cross-Country Training and Test Courses ....................... 4

3.2.2 Clothing and Equipment ................................. 5

3.2.3 Standard Navigational Equipment............................ 14

3.3 Procedures ............................................ 15

3.3.1 Experimental Design ................................... 15

3.3.2 Training.......................................... 20

3.3.3 Testing .......................................... 22

4. Results ................................................. 22

4.1 Frequency of Access to Information ............................. 22

4.2 Mission Tasks .......................................... 22

4.2.1 Navigation ........................................ 23

4.2.2 Target Detection and Identification ........................... 23

4.2.3 Global Situational Awareness (probe questions) .................... 24

4.2.4 Threat Recognition .................................... 26

4.3 Overall Mission ......................................... 26

4.4 Workload............................................. 27

4.4.1 Ratings of Workload Factors............................... 27

4.4.2 Overall Workload .................................... 29

5. Discussion .............................................. 31

6. Conclusions and Recommendations ............................. 34

References ................................................... 35

Appendices

A. Survey and Results........................................ 37

B. Situational Self-Efficacy (SSE) Scale............................. 51

C. Demographic Questionnaire .................................. 53

D. Environmental Symptoms Questionnaire (ESQ) ...................... 55

E. National Aeronautics and Space Administration-Task Load Index (NASA-TLX) .. 59

F. Post-Run and Post-Test Questionnaires............................ 63

Report Documentation Page ....................................... 69
iv

Figures

 1. The trekker helmet-mounted display ................................ 5

 2. DASHER system ........................................... 6

 3. Keypad ................................................. 7

 4. Map display and system status information ............................ 8

 5. Navigational display ......................................... 9

 6. Time to waypoint display ...................................... 10

 7. Enemy unit position display ..................................... 11

 8. Friendly unit position display .................................... 11

 9. Fire support display .......................................... 12

10. Ammunition status display...................................... 12

11. Minefield locations display ..................................... 13

12. Potential ambush sites display.................................... 13

13. NBC contaminated areas display .................................. 14

14. Experimental condition matrix ................................... 15

15. Ranger formation maintained by fire team in all missions ................... 21

16. Main effect of information availability on the number of targets detected and

identified by team leaders ...................................... 23

17. Probe question responses: Mean sensitivity (d’)......................... 25

18. Mean number of threats recognized ................................ 26

19. Main effect of information availability on team leader ratings of effort ........... 28

20. Main effect of information availability on team leader ratings of frustration ........ 28

21. Team member ratings of frustration ................................ 29

22. Overall workload experience of the team leaders ........................ 30

23. Main effect of information management on the overall workload experience

of team members ........................................... 31

Tables

 1. Information keys and data displayed ................................ 8

 2. Order of presentation ......................................... 16

 3. Dependent variables and measures of performance ....................... 17

 4. Measures of overall mission performance............................. 19

 5. ANOVA results of the number of targets detected and identified by team leaders ..... 23

 6. Measures of sensitivity (d’) by team and level of information availability and

information management based on probe question responses ................. 25

 7. ANOVA results of probe question responses ........................... 25

 8. ANOVA results of threat recognition ............................... 26

 9. ANOVA results of team leader ratings of effort ......................... 27

10. ANOVA results of team leader ratings of frustration ...................... 27

11. ANOVA results of team member ratings of frustration ..................... 29

12. ANOVA results of overall workload (team leaders)....................... 30

13. ANOVA results of overall workload (team members)...................... 31
1

THE EFFECTS OF INFORMATION AVAILABILITY AND INFORMATION

MANAGEMENT ON THE PERFORMANCE OF DISMOUNTED MILITARY TEAMS

1. Background

Advanced sensor and display technologies promise to increase dismounted soldier performance

and the potential for mission success by providing the soldier with more information about the

battlefield and by increasing situational awareness (SA). SA has been defined in many different

ways (National Research Council, 1997). Endsley (1988) describes it as “the perception of the

elements in the environment within a volume of time and space, the comprehension of their

meaning and the projection of their status in the near future.”

For the soldier, SA entails both knowledge of the larger battlefield (global SA) and awareness

of the environment that immediately surrounds him (local SA). SA can be affected by many

factors. Decreases in awareness can be affected by too much information as well as too little. It

can be affected by the technology used to display this information and the format in which the

information is displayed. Environmental factors and increases in physical and cognitive

workload and stress may well compound the degrading effects of an information display that

is poorly designed.

It is expected that in the future, much of the information about the battlefield will be presented to

the soldier visually on a helmet- or head-mounted display (HMD). Research has shown that

information presented visually on an HMD can enhance position determination and increase

navigational efficiency by as much as 22% over conventional navigational tools (Glumm et al.,

1998).

Currently, dismounted soldiers navigate with a lensatic compass and a paper map. They count

their paces to determine the distance they travel. They use a protractor to calculate distances and

bearings to objectives and to plot the position coordinates of objects and other units within their

area of operation. Such manual computations and notations are time consuming, subject to error,

and may cause significant increases in mental workload.

In today’s battlefield, command information is typically communicated to unit leaders auditorily

via radio transmission. A recent study discovered that soldiers maintained a greater awareness of

their position with respect to waypoints, targets, and other units when information was presented

visually on an HMD than when the same information was presented auditorily in verbal

messages (Glumm, Branscome, Patton, Mullins & Burton, 1999). The participants in this study

noted that information transmitted auditorily required more memorization and was not as easily

recalled as information presented visually. In the visual mode, graphic representation of object

type and position on the HMD may have facilitated “chunking” of information. The same
2

information, provided auditorily in verbal messages, was presented in series rather than in

parallel, and transformation of these data into a meaningful picture of the battlefield that could be

easily recalled may have been more difficult.

Research and related literature about memory indicate that information must be rehearsed in

order for it to be retained. Even with rehearsal, memory of this information can decay over time.

The more information that is stored in short-term or working memory, the more rapid this decay

and the lower the probability of correct recall (Van Cott & Warrick, 1972). According to Card,

Moran, and Newell (1983), the visual image stored in working memory decays more rapidly than

the auditory image store, but the capacity of the visual image store is larger than that of the

auditory image store.

As the quantity of information that is provided to the soldier increases, the probability that this

information can be accurately recalled is reduced. One would expect that an increase in the

frequency at which this information is reviewed or “rehearsed” might increase retention. Also,

the more recent the review, the more likely the information would be remembered. The need to

frequently refer to a visual display to refresh memory, however, poses an obvious disadvantage.

In Glumm et al. (1999), participants noted that they could retrieve auditory information while

moving but needed to stop to view the information presented on the HMD. The soldiers claimed

that during these moments, they were temporarily distracted and unaware of their immediate

surroundings.

The extent to which one task might interfere with the performance of another task depends on

many factors. The theory of multiple resources (Wickens, 1984) suggests that a number of

resource capacity channels are used to perform a task. These channels have distinct functions,

and each channel is limited in capacity. Given this, performance of a task(s) is expected to be

affected by the magnitude of the demand on each resource, the efficiency of each resource used

in the performance of a task, and the extent to which two tasks performed concurrently might

compete for the same resources.

Attentional conflicts and losses in local SA, which are attributed to the use of HMDs, are a

concern, as is the potential risk of information overload associated with large increases in the

quantity of information provided. Previous field studies (Glumm et al., 1998 & 1999) focused on

the effects of HMDs and display modality on the performance of the individual soldier. The

present study expands this investigation by examining the effects on mission performance of the

availability of information to fire team leaders on an HMD and team support in managing this

information.

In the development of the experimental plan, a survey was administered to 42 infantry personnel

to identify measures of mission success and associated tactical information that would facilitate

mission accomplishment (see Appendix A). A mission description was provided upon which the

soldiers would base their responses. The survey asked (a) When the mission is over, how do you

know that you have been successful in performing your mission, that is, what are your measures
3

of success? (b) What information do you need, and (c) when do you need to access this

information in order to achieve these measures of success? To help the soldiers answer these

questions, lists of measures, types of information, and frequencies at which information could be

accessed were provided from which soldiers could choose. The survey participants could also

add to these lists as desired. The results of the survey are shown in Appendix A, Tables A-1

through A-3. The list of mission success indicators, shown in Table A-1, and the associated

information requirements, also shown in Table A-2, are ordered on the basis of how often each

item was selected by the survey participants. The indicators of mission success that were chosen

most often were used in the selection of mission tasks performed in the field study that followed.

The survey results were also used to derive measures of task performance and weighting factors

to compute an overall measure of mission accomplishment. In the present study, most

information listed in Table A-2 was available to the participants, except for information judged

least likely to affect the achievement of the indicators of success selected. As shown in

Table A-3, the survey participants indicated that in order to achieve the selected measures of

success, most information needs to be provided only at the operations order (OPORD) and when

such information changes.

The present study was a 2 x 2 fixed factor design in which Marine Corps fire teams performed

missions in each of four experimental conditions. These four conditions represented a combination of two levels of information availability and two levels of information management. For this

study, information availability was defined by how often the team leader could access tactical

information displayed on the HMD. The two levels of information availability were at the

OPORD and (a) when changes in the position of other units occurred, and (b) when changes in

unit position occurred and any other time during the mission. In this study, information

management was defined by the level of assistance that team members could provide to the team

leader in tracking and recalling information about the battlefield situation and changes that had

occurred. The two levels of information management were (a) team leader only and (b) team

leader with team support.

The following were hypothesized for this investigation:

1. As the availability of information on the HMD increases, global SA will increase, as

measured by the number of correct responses to probe questions and the number of threats

correctly acknowledged within the designated distance from the team.

2. As the availability of information on the HMD increases, navigational efficiency will

increase as measured by distance traveled.

3. As the availability of information increases, local SA of the team leader will decrease

as measured by the number of targets that the team leader detects in the surrounding woods.

4. Local SA of the team as a whole will not be affected by increases in the availability

of information to the team leader on the HMD.
4

2. Objectives

The objective of this field investigation was to examine the effects of the availability of information on an HMD and team support in managing information on SA (local and global), team

performance, and perceptions of workload.

3. Method

3.1 Participants

Eight Marine Corps fire teams participated in this investigation. Each of the eight teams

consisted of a fire team leader and three team members whose ranks included sergeants,

corporals, and lance corporals. The 32 Marine participants ranged in age from 18 to 29 years

(mean = 22 years) with approximately 1 to 6.5 years in service (mean = 3.2 years). The military

occupational specialty (MOS) of the fire team leaders and their team members was equivalent to

the Army MOS of 11B (infantryman). The fire team leaders had approximately 2 to 3 years’

experience in that position. Most of the Marines who participated in the study knew each other.

Although many had worked together as part of the same company, few had worked together in

the teams that had been organized to participate in this study. The voluntary, fully informed

consent of the volunteers used in this research was obtained as required by 32 Code of Federal

Regulations (CFR) 219 and Army Regulation (AR) 70-25. The investigators have adhered to the

policies for protection of human subjects as prescribed in AR 70-25.

3.2 Apparatus

3.2.1 Cross-Country Training and Test Courses

The length of the training course was 600 meters. The course consisted of three segments or legs

that intersected four waypoints. Each leg of the course was 200 meters long. The terrain was

wooded and except for two moguls, was generally flat.

The length of the test course was 3 kilometers. The course consisted of four legs that intersected

five waypoints. The lengths of the legs were 550, 700, 850, and 900 meters. The terrain was flat

and densely wooded.

Three-dimensional wooden silhouettes representing enemy and friendly personnel were

positioned along each leg of the training and test course. A three-digit number that was painted

on each “target” was used to identify it as an enemy or as a friend. This target identification code

was changed for each mission to minimize learning effects.
5

3.2.2 Clothing and Equipment

All participants wore the Marine Corps equivalent of the standard battle dress uniform and the

personal armor system for ground troops (PASGT) helmet. All fire team leaders and team

members carried a dummy M16 rifle.

3.2.2.1 Helmet-Mounted Display

The fire team leader was the only member of the team to wear an HMD. The HMD was part of a

system developed by Rockwell International, called the Trekker (see Figure 1). The weight of the

HMD is approximately 0.45 kg (1.0 lb). The headset consists of an occluding, monocular display

developed by Kopin. The display is a monochrome active matrix liquid crystal display with 640

horizontal by 480 vertical lines of resolution. Focus and brightness controls are integrated into

the headset. The display slides left or right along the top of the unit to accommodate the desired

viewing eye. The monocular assembly can be adjusted for eye relief and displaced vertically for

stowage. In this investigation, the display was positioned over the non-aiming eye for viewing

and was stowed when not in use.

During the study, auditory messages were presented to the fire team leader through two small

speakers (Electro Voice, Model 1993) installed in the PASGT helmet. These auditory messages

were automatically initiated at predetermined coordinates along the course. They included alerts

about changes in unit position, arrivals at waypoint, the status of the global positioning system

(GPS) and electronic compass, map access, and probe questions that queried the team leader

about the current battlefield situation.

Figure 1. The trekker helmet-mounted display.
6

3.2.2.2 Digitally Aided Soldier for Human Engineering Research (DASHER) System

The fire team leader also wore a backpack that contained the DASHER system (see Figure 2).

DASHER was developed by Sytronics, Inc., of Dayton, Ohio, and consists of a GPS receiver, an

electronic compass, and a small Pentium computer. The system is powered by a 12-volt battery

and weighs approximately 10 kg (22 lb). The single-board GPS receiver (Micro-Plugger Engine1), developed by Rockwell International, is capable of providing position information within

±10 m of accuracy. The electronic compass (C100), developed by KVH1 Industries, is based on

magnetic flux-sensing technology. The compass provides ±0.5 degree (±10 mils) accuracy with

0.1 degree (1 mil) resolution.

Figure 2. DASHER system.

DASHER is operated as a real-time interactive device running in a Linux environment. In this

study, DASHER automatically initiated mission events and tasks, generated the visual displays

and auditory messages, and recorded soldier performance. The major portion of the system

 

1Not an acronym
7

software is written in Perl and Perl-Tk (a graphical user interface for Perl). GPS and compass

programs, written in “C,” ran simultaneously, generating information about the location and

orientation of the DASHER unit. This information is retrieved once a second by the Perl

program. DASHER used a position-based script to simulate connectivity with a command

network. For this study, coordinates of mission events were programmed in the computer, along

with the positions of waypoints, friendly and enemy units, minefields, potential ambush sites,

and areas contaminated with nuclear, biological, or chemical (NBC) agents. A computer routine

calculated the distance and bearing of the fire team leader, who wore the DASHER, with respect

to the programmed coordinates. A mission event was initiated when the fire team leader was

within a 20-meter radius of a position coordinate.

3.2.2.3 Keypad

The fire team leader accessed tactical information and responded to mission events via a keypad

that he wore on his belt. The keypad consisted of labeled buttons that included nine information

keys and four function keys (see Figure 3). The data that were displayed on the HMD when each

of the information keys was depressed are listed in Table 1.

Figure 3. Keypad.

As shown in Figure 3, nine keys were also labeled 1 through 9. These keys, along with three of

the four function keys, were used in the performance of mission tasks. The numbered keys were

used along with the ENTER button in the target detection-identification task. The ENTER button

was also used in conjunction with the MINE, AMB, and NBC keys to acknowledge the position

of the fire team with respect to threats in the threat recognition task. The YES and NO keys were

used to respond to probe questions that were automatically initiated at predetermined area

coordinates along the course. The START button was used to indicate commencement of travel
8

to the next waypoint, and the HUSH button was used to acknowledge that an auditory message

was received.

Table 1. Information keys and data displayed

______________________________________________________________________________

Key Information

______________________________________________________________________________

NAV distance from path and waypoint, and azimuth orientation

TIME time remaining to reach the next waypoint

ENE types of enemy units and distances

FRD types of friendly units and distances

FSUP call signs, type, and distances of supporting units

AMMO clips remaining per soldier

MINE distances from minefields

AMB distances from potential ambush sites

NBC distances from areas contaminated by nuclear, biological, or chemical agents

______________________________________________________________________________

3.2.2.4 Information Displays

Figure 4 depicts the map of the area of operation and system status messages that were displayed

on the HMD worn by the fire team leader. This information was available to the team leader at

all times in all experimental conditions. The map display depicted the waypoints to which the

team was to travel and the “optimum” straight-line path between these points. The system status

information provided to the right of the map showed the estimated position error (EPE) of the

GPS and operational condition of the GPS and electronic compass.

GPS EPE: 10m

Figure 4. Map display and system status information.
9

The data displayed on the HMD upon depression of each of the information keys is described

next and is depicted in Figures 5 through 13. Only one key could be pressed at a time, and only

the information requested was provided. The information requested remained displayed for 1

minute or until another key was pressed.

3.2.2.4.1 Navigation

When the NAV key was pressed, the waypoint to which the team was traveling was darkened.

An icon representing the current location and orientation of the fire team leader was overlaid on

the map (see Figure 5). This icon, shown as a circle with a pointer, depicted the location of the

fire team leader to the left or right of the optimum path and his azimuth orientation. It also

showed his distance from the next waypoint and the bearing that he must take to achieve it.

Position information was provided in alphanumeric form to the right of the map display.

GPS EPE: 10m

Path: 20 m L

 Azimuth 15°

Waypoint: 250 m

 Bearing 63° 

NAVIGATION

Figure 5. Navigational display.

3.2.2.4.2 Time to Reach Waypoint

Depression of the TIME key provided information about the time remaining to reach the

waypoint to which the team was currently traveling and the times designated for travel between

subsequent waypoints (see Figure 6). An icon representing the distance of the fire team leader

from the next waypoint was also provided; however, unlike the navigation display, this icon did

not depict the location of the fire team leader with respect to the “optimum” straight-line path or

his azimuth orientation.
10

GPS EPE: 10m

TIME between WPs

LEG 2

5 min

LEG 3

41 min

LEG 4

33 min

Figure 6. Time to waypoint display.

3.2.2.4.3 Enemy and Friendly

a. Unit Positions

In all conditions, information about the position of enemy units could be accessed by the

pressing of the ENE key whenever a change in the position of an enemy unit occurred. Likewise,

information about the position of friendly units could be accessed by the pressing of the FRD key

whenever a change in the position of a friendly unit occurred. When a unit moved, the fire team

leader was provided an auditory message that identified the unit and the new location. For

example, “Alert. Change. Enemy light infantry unit has moved to 398100 Northing 4367200

Easting.” The message was repeated every 15 seconds to allow time for the new coordinates to

be recorded on a paper map.

When the ENE or FRD key was pressed, symbols depicting the type and location of the units

were overlaid on the map display (see Figures 7 and 8). The location of the fire team leader with

respect to these units was depicted by a circle. Unlike the navigational display, this icon only

showed the distance of the fire team leader along the course. It did not depict his azimuth

orientation or any lateral deviation from path center. Alphanumeric information about the

distance of units to the front of the team was presented to the right of the map. Data about units

to the rear of the fire team were not provided although the symbols representing these units

remained displayed. For units on subsequent legs of the path, the data represented the distance of

the units from the start of the leg upon which the units were situated.
11

GPS EPE: 10m

ENEMY

LEG 2

Artillery 230 m L

LEG 3

Mechanized 80 m R

Armor 480 m L

LEG 4

Mechanized 240 m L

Light Infantry 540 m L

Figure 7. Enemy unit position display.

GPS EPE: 10m

FRIEND

LEG 2

Mechanized (T71) 130 m R

LEG 3

Mechanized (V52) 180 m R

Armor (F 86) 440 m R

Light Infantry (L37) 800 m L

LEG 4

Light Infantry (X27) 320 m R

Artillery (K63) 440 m L

Mechanized (R29) 620 m R 

Figure 8. Friendly unit position display.

b. Fire Support

Depression of the FSP button provided information about available fire support within the area

of operation. Symbols depicting the type and location of these supporting units were overlaid on

the map display, along with an icon depicting the current location of the fire team leader (see

Figure 9). No other friendly units were depicted. As in the displays depicting enemy and friendly

unit positions, the alphanumeric information presented to the right of the map display represented the distance of supporting units forward of the team. No data were provided about the
12

position of supporting units to the rear of the team, although symbols representing these units

remained displayed. The position of supporting units on subsequent legs of the path represented

the distance of these units from the start of the leg upon which the units were situated.

GPS EPE: 10m

FIRE SUPPORT

LEG 3

Armor (F 86) 440 m R

LEG 4

Light Infantry (X27) 320 m R 

Figure 9. Fire support display.

c. Ammunition Status

Depression of the AMMO key provided information about the current number of clips of

ammunition available per team member (see Figure 10). This count assumed an initial

distribution of seven clips per soldier, an expenditure of one clip for each target identified as

enemy, and redistribution of the remaining clips among the team members.

GPS EPE: 10m

AMMO (clips per 

 man)

5

Figure 10. Ammunition status display.
13

3.2.2.4.4 Threats

Upon depression of the MINE, AMB, or NBC keys, symbols depicting the location of

minefields, potential ambush sites, and areas contaminated with NBC agents were overlaid on

the map display, respectively (see Figures 11 through 13). Alphanumeric information provided to

the right of the map display represented the distance of threats to the front of the team. For

subsequent legs, these data represented the distance of threats from the start of the leg upon

which the threats were situated. As in other information displays, the location of the fire team

leader was depicted by a circle.

GPS EPE: 10m

MINE

LEG 2

30 m

LEG 3

300 m

LEG 4

(Unknown)

Figure 11. Minefield locations display.

GPS EPE: 10m

AMBUSH

LEG 3

(Unknown)

LEG 4

100 m

Figure 12. Potential ambush sites display.
14

GPS EPE: 10m

NBC

LEG 3

600 m

LEG 4

460 m 

Figure 13. NBC contaminated areas display.

3.2.3 Standard Navigational Equipment

In all conditions, each fire team was provided with standard navigational tools to assist them in

navigation and position determination throughout the mission. These tools included a paper

version of the map presented on the HMD, a protractor, a lensatic compass, and a hand-held

GPS.

3.2.3.1 Paper Map

The paper map had been derived from digital ortho-photography and was accurate to within 0.46

meter (1.5 feet). It depicted streams, marsh, trees and foliage, dirt paths, and improved roads, and

other landmarks provided on standard military maps. A legend defining these terrain features and

landmarks was included. The scale of the map was increased from the standard 1:50000-meter

military map to 1:6000 meters, given that the area of operation in this field experiment would

appear the size of a postage stamp on the standard scale map and would lack the needed detail. A

protractor, similar to that of the standard military protractor (graphic training aid 5-2-12), was

sized to conform to the scale of the map.

The paper map was pre-annotated for each of the four tactical scenarios to avoid errors in

transposition. Information provided on the map included the distance and bearing to each

waypoint and the time requirements to reach these points. Enemy and friendly unit positions,

available fire support and their call signs, and potential threats within the area of operation were

also shown. The paper map depicted the battle situation at the time of the OPORD.

In all conditions, access to the paper map was restricted to every 200 meters along the course and

when changes in unit position occurred. Auditory messages were automatically presented to
15

indicate when the paper map could be consulted. Access to the paper map was also monitored by

one of the researchers who accompanied the fire team on their mission.

3.2.3.2 Lensatic Compass

A standard military lensatic compass was provided to each team for determining azimuth

orientation. The compass has a vertical sight in the lid and a separate lens that the soldier uses to

align a landmark and read the bearing.

3.2.3.3 GPS

A hand-held GPS receiver (AN/PSN-11), developed for the military by Rockwell International,

was provided to each team. Like that incorporated in the DASHER system, the GPS provided an

accuracy of ±10 meters. The GPS was used in the navigational mode and provided information

similar to that presented on the HMD. This information included the distance of the user in

meters to the left or right of path centerline and his distance and azimuth orientation with respect

to the next waypoint.

3.3 Procedures

3.3.1 Experimental Design

The study was a fixed two-factor experiment with information availability (OPORD and

anytime) and information management (team leader and team) all as within-subject effects. The

experimental condition matrix for this field investigation is shown in Figure 14. The order of

presentation of the experimental conditions was counterbalanced (see Table 2).

 Information Availability

OPORD Anytime

Team Leader A C

Information 

Management

Team B D

Figure 14. Experimental condition matrix.
16

Table 2. Order of presentation

______________________________________________________________________________

Order of Presentation

Test Period Day 1 Day 2

Time of Day a.m. p.m. a.m. p.m.

Team

______________________________________________________________________________

 1 A B* D C

 2 B A* C D*

 3 A D B C

 4 D A C B

 5 C B D A

 6 B C A D

 7 D C A B

 8 C D B A

______________________________________________________________________________

*The data from these runs could not be used in the final analysis.

3.3.1.1 Independent Variables

The independent variables were information availability and information management. There

were two levels of each of these variables. The two levels of information availability were at the

OPORD and (a) when changes in the position of other units occurred, and (b) when changes in

unit position occurred and any other time during the mission. The two levels of information

management were (a) team leader only and (b) team leader with team support.

There were four experimental conditions or combinations of levels of the independent variables.

In each of the four conditions, an OPORD was delivered to the fire team leader and his team

members before the mission. During the OPORD, the fire teams were briefed about the mission

and the current battlefield situation. The team leader was provided with an annotated paper map

that included the scenario details. During each mission, access to information on the HMD was

controlled by the DASHER system, based on the experimental condition input before each run.

In the OPORD-Team Leader condition, the team was briefed about the tactical scenario at the

OPORD, and the team leader was provided time to study the battlefield situation before the

mission began. In this condition, the team leader could only access information about enemy or

friendly unit positions and then only when the position of a unit changed. Team members could

not assist the team leader in keeping track of the different types of information that needed to be

recalled during the mission.

The OPORD-Team condition was the same as the OPORD-Team Leader condition except that

the team members could now assist the team leader in remembering any or all of the scenario

details. In this condition, the team leader could distribute information among his team members

and could consult with them any time during the mission. The team members could also assist
17

the team leader in answering probe questions. They could alert him of the proximity of a

potential threat or remind him of the call sign, type, and location of a supporting unit.

In the Anytime-Team Leader condition, the team leader could access any or all information

displayed on his HMD at any time during the mission. However, as in the OPORD-Team Leader

condition, his team members could not assist him in responding to probe questions or other tasks

that required recall of the tactical situation.

In the Anytime-Team condition, the team leader could access information at any time on the

HMD and distribute any or all of the information among his team members. The team members

could be consulted at any time and could provide full support in response to probe questions or

other events that involved information recall.

3.3.1.2 Dependent Variables

The dependent variables included performance in navigating, target detection-identification,

probe questions, and threat recognition. A measure of overall mission performance was also

computed, and subjective ratings of workload were obtained (see Table 3).

Table 3. Dependent variables and measures of performance

______________________________________________________________________________

Dependent Variables Measures

______________________________________________________________________________

Navigation Distance traveled (meters)

Velocity (meters per minute)

Target Detection and Identification Number of targets detected and correctly identified by the team

leader and the team as a whole

Probe Questions Sensitivity (d’) computed from the number of hits, misses, correct

rejections, and false alarms in responses to probe questions

Threat Recognition Number of threats correctly identified within 20 to 50 meters of

team position

Overall Mission Performance Compilation of scores on missions tasks (see Table 4)

Workload (NASA-TLXa) Subjective ratings or workload sources (i.e., mental, physical,

temporal, performance, effort, and frustration) and overall

workload scores

______________________________________________________________________________

a

NASA-TLX = National Aeronautics and Space Administration-Task Load Index

A description of the dependent variables, associated tasks, and measures of performance follows.

3.3.1.2.1 Navigation

Each fire team was instructed to navigate between waypoints as quickly as possible, deviating

from the “optimum” straight-line path only as far as necessary to avoid obstacles. Measures of
18

distance traveled and travel velocity were computed from position information that was recorded

once a second by the DASHER system.

3.3.1.2.2 Target Detection and Identification (local SA)

Twenty targets were positioned at random distances along the course. Five targets were situated

along each of the four legs. The fire team leader and team members were instructed to identify

these targets as enemy or friendly, based on a three-digit number that was painted on each target.

The target identification code was changed for each mission to minimize learning effects. When

a target was detected, the team member who spotted the target announced “enemy” or “friendly”

and stated the target number. The target identification and target number were entered in the

computer by the team leader. Performance of this task was based on the number of targets

detected and correctly identified by the team leader and those detected and identified by the team

as a whole. The number of targets detected by the team leader was assessed as a measure of his

awareness of the local situation.

3.3.1.2.3 Probe Questions (global SA)

Twenty-four probe questions were administered to the fire team leader at predetermined

coordinates along the course. Six probe questions were administered along each of the four legs.

Of these six questions, one question was posed about the position of the team with respect to

waypoints and one question about ammunition status. Two questions were posed about enemy

and friendly unit positions and unit type (i.e., armor, artillery, mechanized or dismounted

infantry) and two questions about available fire support and their call signs. The team leader

responded to each probe question by pressing the YES or NO key on his keypad. The team

leader could not access information on the HMD until he pressed one or the other key. The signal

detection sensitivity statistic (d') was used to analyze responses to probe questions.

3.3.1.2.4 Threat Recognition (global SA)

Threat recognition performance was based on timely and accurate “communication” of

information about threats (i.e., minefield, ambush, NBC). Performance of this task was

determined by the number of potential threats correctly identified within a designated distance of

the team (i.e., 20 to 50 meters). There were 10 threats along the course two to three threats in

each of the four legs.

3.3.1.2.5 Workload

The NASA-TLX was administered to each participant at the end of each mission. The NASATLX uses rating scales to assess mental, physical, and temporal demands, performance, effort,

and frustration. In this technique, a weight is initially obtained for each of the six workload

factors, based on the responses of the participant to pair-wise comparisons among these factors.

In these comparisons, the six factors are presented in 15 possible pairs and for each pair, the

participant is asked to circle the factor that he or she perceived contributed more to his or her

workload experience. The participant then completes rating scales that provide a measure of the

magnitude of the workload for each factor. Those factors perceived by the participant to be most
19

important in his or her workload experience are given more weight in the computation of an

overall workload score.

3.3.1.2.6 Overall Mission Performance

Table 4 lists the performance measures and scoring techniques used to compute a measure of

overall mission performance. The performance measures chosen to be included in this overall

score were selected for their relevance to one or more “indicators of mission success” identified

in the earlier survey of infantry personnel who judged these indicators to be most reflective of

mission accomplishment. The Situational Self-Efficacy (SSE) scale shown in Appendix B and

the Environmental Symptoms Questionnaire (ESQ) shown in Appendix C were used to obtain a

measure of the extent to which the team was “prepared for the next mission.” The SSE was

administered before the mission began. The ESQ was administered before the mission began and

after it ended.

3.3.2 Training

The duration of training and testing for each of the eight fire teams was 1 week. Two fire teams

were trained and tested during a 1-week period. Training included both classroom and field

instruction. Participant screening and orientation was conducted on the morning of the first day,

followed by classroom instruction and field training.

3.3.2.1 Participant Screening and Orientation

The military volunteers were briefed about the purpose of the study, the study design, the

training and testing schedule, the procedures to be followed, and any risks involved in their

participation. All participants were required to read and sign a statement of informed consent. A

visual acuity test at far and near distances was administered to the fire team leaders to ensure

20/20 vision in one eye and at least 20/30 in the other eye, corrected or uncorrected. The fire

team leaders were also required to pass tests of color and stereo-vision. All participants

completed a questionnaire to obtain pertinent demographic information (see Appendix D).

3.3.2.2 Classroom Instruction

Classroom instruction began in the afternoon of the first day. During this period, the fire team

leaders and their team members were briefed about the tasks to be performed during their

missions, the information needed to perform these tasks, and the equal importance of all tasks to

overall mission performance. The team leaders and their team members were briefed about the

design and operation of the equipment to be worn by the fire team leader (i.e., the DASHER

system, the HMD, and the keypad). All were shown visuals of the information displays and the

type of data that each display would provide. The use of the keypad in accessing the various

types of information and responding to each mission task was also demonstrated.

All participants received instruction about the use of the standard navigational equipment (i.e.,

lensatic compass, hand-held GPS, protractor and paper map). At the conclusion of this portion of
20

the instruction, each team designated one member of the team to use the compass and another

member to operate the hand-held GPS. The team leader who would be responsible for plotting

changes in unit position on the paper map received instruction about the re-scaled protractor and

map, along with practice in plotting coordinates.

Table 4. Measures of overall mission performance

______________________________________________________________________________

Indicators of Mission Success Measures Scoring Technique Points

______________________________________________________________________________

(1) Maintained communication Number of threats correctly reported Ten (10) threats, each 2.0 points 20

 up the chain of command within 20 to 50 meters of team

(2) Did not run out of Number of correct responses to probe Four (4) probe questions, each 5.0 20

 ammunition questions about ammunition status points

(3) All the enemy were Number of enemy targets detected and Ten (10) enemy targets, each 2.0 20

 destroyed correctly identified points

(4) All the men in my unit Number of casualties (i.e., enemy targets Ten (10) possible incidents, 2.0 points 20

 survived identified as friendly) deducted per incident

(5) Maintained communication Team ratings of adequacy of informa- Adequacy rated on a 5-point scale: 20

 down the chain of command tion, communication within team, and (high = 5; low = 1); mean rating

team performance on five questions computed for

each team member and summed

for team score

(6) Seized and occupied terrain Time to reach Objective (Waypoint 3) Arrival at Objective within designated 5

time, 5.0 points

Correct response to probe question about One (1) probe question, 5.0 points 5

ammunition status before arrival at

Objective

Number of men in team upon arrival Four (4) men in team, 2.5 points 10

at Objective (based on number of casual- per man

ties in preceding legs of course)

(7) No incidents of fratricide Number of friendly personnel identified Ten (10) possible incidents, 2.0 points 20

as enemy deducted per incident

(8) Received adequate Number of correct responses to probe Five (5) probe questions, each 4.0 20

 supporting fires questions about available fire support points

(9) Physically and mentally Ratings of confidence that the mission Confidence in mission on 10-point 10

 prepared for mission will be successful (SSE) scale (high = 10; low = 1); mean

computed for each team

Ratings of symptom severity in pre- and For each team member whose post- 10

post-test administration of ESQ test rating of severity of two or more

symptoms exceeds pre-test ratings by

two or more points, deduct 2.5 points

(10) Reached waypoints on time Time to reach each waypoint Four (4) waypoints, each 5.0 points 20

Total Score 200

______________________________________________________________________________
21

During the training period, the participants also received instruction in completing questionnaires

that would be administered during the test period. These questionnaires included the SSE, the

ESQ, and the NASA-TLX.

3.3.2.3 Field Training

During field training, each team completed successive runs through the training course in one

experimental condition until they reached asymptote in navigation time and targets detected.

During each run, the two teams navigated the training course in opposite directions, each

accompanied by a member of the research team. After each run through the training course, the

researcher re-programmed the DASHER system for a different scenario. The team leader was

provided with a new paper map annotated for that scenario, and time was allowed to study the

tactical details with his team, as appropriate.

During both training and testing in each experimental condition, each fire team was required to

maintain a ranger formation as shown in Figure 15. This formation had been agreed to by the

researchers and the Marine Corps participants as appropriate for the mission, the terrain, and the

objectives of the research.

Point Man with GPS

Fire Team Leader with HMD and DASHER system

Researcher

Fire Team Member with lensatic compass

Fire Team Member

Figure 15. Ranger formation maintained by fire team in all missions.

3.3.3 Testing

Before testing in each condition, an OPORD was delivered to the fire teams by a senior

noncommissioned officer. A hard copy of the OPORD was also provided, along with an

annotated paper map. After the OPORD and before the test run, each team was provided the time

they deemed necessary to prepare for the imminent mission. Immediately before the run, the

team leaders and team members were administered the SSE and the ESQ.
22

Each team was then driven to their respective starting points on the test course. They were

reminded of the procedures to be followed during their missions and that each task to be

performed was of equal importance. As during training, each team navigated the course in

opposite directions, accompanied by a member of the research team.

At the conclusion of the run, the team leaders and their team members were administered the

ESQ and the NASA-TLX. The team leaders and team members were also asked to complete

post-run questionnaires shown in Appendix F, respectively.

For each day of test, the time between runs in each of the two experimental conditions was

approximately 2 hours. During this period, the teams were provided lunch, a rest break, and the

OPORD for the next test run.

At the conclusion of testing in all conditions, each team leader was asked to complete a post-test

questionnaire.

4. Results

4.1 Frequency of Access to Information

The frequencies with which team leaders accessed information on the HMD in conditions where

such access was unrestricted (i.e., Anytime-Team Leader and Anytime-Team) were subjected to

an analysis of variance (ANOVA) with level of information management (i.e., team leader and

team) as a within-subjects effect. In both conditions, navigational information was accessed more

often than any other type of tactical information; however, no significant differences between

levels of information management were revealed in the frequency with which the teams accessed

information of a particular type.

4.2 Mission Tasks

Performance data obtained for each mission task were subjected to a two-way ANOVA with

levels of information management and information availability as within-subjects effects. The

results of the analysis follow.

4.2.1 Navigation

The results of the ANOVA of distance traveled and travel velocity data did not reveal any

significant effects or interactions of information availability and information management on

navigation performance.
23

4.2.2 Target Detection and Identification

No significant main effects or interactions were revealed in the analysis of the number of targets

detected and correctly identified by the team as a whole (i.e., team leader and team members).

However, as shown in Table 5, a significant effect of information availability was found for the

number of targets detected and identified by team leaders (F[1,15] = 4.69; p = < .05). This

finding indicates that team leaders detected fewer targets during missions in which information

could be accessed at any time on the HMD by comparison to missions in which access to

information on the HMD was restricted (see Figure 16).

Table 5. ANOVA results of the number of targets detected and identified by team leaders

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 283.3 7 40.471 12.619 0.000

Availability 15.043 1 15.043 4.69 0.047

Management 1.14E-02 1 1.14E-02 0 0.985

Availability*Management 1.673 1 1.673 0.522 0.481

Order 43.886 3 14.629 4.561 0.018

Error 48.108 15 3.207

______________________________________________________________________________

0

1

2

3

4

5

Mean 

Number of 

Targets

OPORD Anytime

Information Availability

Targets Detected-Identified by Team 

Leaders

Team Leader

Team

0

1

2

3

4

5

OPORD Anytime

Information Availability

Mean Number of Targets

Figure 16. Main effect of information availability on the number of targets detected and identified

by team leaders.
24

4.2.3 Global Situation Awareness (probe questions)

Responses to probe questions were treated as an assessment of information available in the

participants’ memories. The signal detection sensitivity statistic d-prime (d') was used to analyze

the data. Each response was graded as a hit, miss, correct rejection, or false alarm, which are

defined as follows:

Hit: Answered “Yes” and “Yes” was correct

Miss: Answered “No” and “Yes” was correct

Correct Rejection: Answered “No” and “No” was correct

False Alarm: Answered “Yes” and “No” was correct

From these scores, conditional probabilities of the participants making a particular response were

determined by the following formulas:

p[hit] = number of hits 

number of hits + number of misses

p[false alarm] = number of false alarms 

number of false alarms + number of correct rejections

Based on these probabilities, measures of sensitivity (d') were computed by the following

formula:

d' = z p[hit] - z p[false alarm]

It was assumed that the information requested in the probe questions was equally probable and

normally distributed. The larger the d’, the greater the probability that the participant responded

correctly and less likely by chance. Measures of sensitivity (d’) that are close to or below 0

indicate progressively fewer correct responses and the greater likelihood that correct or incorrect

responses were made by chance. Table 6 lists the d’ computed for each team by level of

information availability and information management. These data show considerable variability

among teams in performance in each of the four experimental conditions.

The results of the ANOVA of probe question responses are shown in Table 7 and are illustrated

in Figure 17. Technically, the analysis did not reveal a statistically significant effect of

information availability (F[1,15] = 4.224; p = .058); however, the results are suggestive of a

potential influence and the need for further study. A decrease in the number of correct responses

to probe questions in conditions in which information could be accessed at any time on the HMD

would be unexpected. No significant effect of information management or interaction between

information availability and information management was found.
25

Table 6. Measures of sensitivity (d’) by team and level of information availability and information

management based on probe question responses

______________________________________________________________________________

Team OPORD-Leader OPORD-Team Anytime-Leader Anytime-Team

______________________________________________________________________________

 1 2.4865 * 0.9278 0.6849

 2 * -0.2527 -0.7655 *

 3 0.6259 0.6071 -0.9679 -0.1134

 4 0.4594 0.9063 -0.2538 1.0205

 5 1.1503 0.1397 0.3186 -0.5724

 6 1.1061 0.9026 0.8794 0.9630

 7 -0.3559 -0.3186 0.4946 0.5244

 8 1.5913 0.0000 1.6406 1.1938

Mean 1.0091 0.2835 0.2842 0.5326

SD 0.9003 0.5207 0.8955 0.6495 

*No data for mission

 SD = standard deviation

Table 7. ANOVA results of probe question responses

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 7.925 7 1.132 4.917 0.005

Availability 0.973 1 0.973 4.224 0.058

Management 0.308 1 0.308 1.339 0.265

Availability*Management 0.424 1 0.424 1.841 0.195

Order 3.803 3 1.268 5.507 0.009

Error 3.453 15 0.230 

0

0.2

0.4

0.6

0.8

1

1.2

Mean 

Sensitivity 

(d')

OPORD Anytime

Information Availability

Probe Question Responses

Team Leader

Team

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

OPORD Anytime

Information Availability

Mean Sensitivity (d')

Figure 17. Probe question responses: Mean sensitivity (d’).
26

4.2.4 Threat Recognition

The results of the ANOVA of the number of threats correctly identified and reported within the

designated distance of the team are shown in Table 8 and are illustrated in Figure 18.

Technically, the analysis did not reveal a statistically significant effect of information availability

(F[1,15] = 4.137; p = .06); however, the results are suggestive of a potential influence and are of

particular interest, given the results of the analysis of probe question responses. Further study is

needed.

Table 8. ANOVA results of threat recognition

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 133.067 7 19.01 4.748 0.005

Availability 16.563 1 16.563 4.137 0.060

Management 0.427 1 0.427 0.107 0.749

Availability*Management 3.59E-02 1 3.59E-02 0.009 0.926

Order 19.217 3 6.406 1.600 0.231

Error 60.057 15 4.004

______________________________________________________________________________

0

1

2

3

4

5

6

Mean 

Number of 

Threats

OPORD Anytime

Information Availability

Threats Recognized

Team Leader

Team

0

1

2

3

4

5

6

OPORD Anytime

Information Availability

Mean Number of Threats

Figure 18. Mean number of threats recognized.
27

4.3 Overall Mission

For each mission, a measure of overall performance was derived from scores on each of the 10

tasks (see Table 4 for description of measures and scoring technique). The scores on each of these

measures were multiplied by a weighting factor derived from the previous analysis of survey

responses. The weighted scores were then tallied to obtain an overall measure of mission

performance for each fire team in each condition of information availability and management.

The tallied scores were subjected to an ANOVA. All effects failed to reach significance at the

.05 level of confidence.

4.4 Workload

4.4.1 Ratings of Workload Factors

Team leader and team member ratings of workload for each of six factors or sources of workload

were subjected to a two-way ANOVA with information management and information availability

as within-subjects effects. The six sources of workload examined in these analyses were mental,

physical, and temporal demands, performance, effort, and frustration. The results of the analysis of

team leader ratings of workload revealed a significant effect of information availability on team

leader ratings of effort (F[1,15] = 11.286; p < .005) and frustration (F[1,15] = 4.928; p < .05).

These findings are shown in Tables 9 and 10 and are depicted in Figures 19 and 20, respectively.

The findings suggest that team leaders expended more effort and were more frustrated in

conditions in which access to information on the HMD was restricted.

Table 9. ANOVA results of team leader ratings of effort

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 146704.6 7 20957.8 10.268 0.000

Availability 23036.13 1 23036.13 11.286 0.004

Management 2703.258 1 2703.258 1.324 0.268

Availability*Management 5344.672 1 5344.672 2.619 0.126

Order 10699.52 3 3566.508 1.747 0.200

Error 30615.64 15 2041.043 

Table 10. ANOVA results of team leader ratings of frustration

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 775842.1 7 110834.6 12.507 0.000

Availability 43672.83 1 43672.83 4.928 0.042

Management 5802.23 1 5802.23 0.655 0.431

Availability*Management 3738.684 1 3738.684 0.422 0.526

Order 27907.22 3 9302.407 1.050 0.399

Error 132927.9 15 8861.859 
28

The results of the analysis of team member ratings of frustration are shown in Table 11.

Although the results that are illustrated in Figure 21 were technically not statistically significant

(F[1, 56] = 3.841; p = .055), they are worthy of note and suggest the need for further study.

0

50

100

150

200

Workload 

Ratings

OPORD Anytime

Information Availability

Effort (Team Leaders)

Team Leader

Team

0

50

100

150

200

OPORD Anytime

Information Availability

Figure 19. Main effect of information availability on team leader ratings of effort.

0

50

100

150

200

250

300

350

400

Workload 

Ratings

OPORD Anytime

Information Availability

Frustration (Team Leaders)

Team Leader

Team

0

50

100

150

200

250

300

350

400

OPORD Anytime

Information Availability

Figure 20. Main effect of information availability on team leader ratings of frustration.
29

Table 11. ANOVA results of team member ratings of frustration

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 1552797.40 23 67512.93 4.704 0.000

Availability 32446.67 1 32446.67 2.261 0.138

Management 43265.06 1 43265.06 3.014 0.088

Availability*Management 55124.86 1 55124.86 3.841 0.055

Order 48592.72 3 16197.57 1.129 0.345

Error 803745.7 56 14352.6

______________________________________________________________________________

0

50

100

150

200

250

Workload 

Ratings

OPORD Anytime

Information Availability X 

Information Management

Frustration (Team Members)

Team Leader

Team

0

50

100

150

200

250

OPORD Anytime

Information Management X 

Information Availability

Team Leader

Team

Figure 21. Team member ratings of frustration.

4.4.2 Overall Workload

Overall workload scores were computed for each team leader and team member from weighted

ratings on each of the six workload factors. The overall workload scores of team leaders and

team members were each subjected to a two-way ANOVA with information management and

information availability as within-subjects effects.

The results of the analysis of the overall workload scores of team leaders are shown in Table 12.

Although the results that are illustrated in Figure 22 are technically not statistically significant

(F[1,15 ] = 4.471; p = .052), they are worthy of note and suggest the need for further study.
30

Table 12. ANOVA results of overall workload (team leaders)

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 11011.86 7 1573.123 20.017 0.000

Availability 351.346 1 351.346 4.471 0.052

Management 35.855 1 35.855 0.456 0.510

Availability*Management 32.12 1 32.12 0.409 0.532

Order 171.215 3 57.072 0.726 0.552

Error 1178.869 15 78.591

______________________________________________________________________________

0

10

20

30

40

50

60

70

Workload 

Ratings 

(Weighted)

OPORD Anytime

Information Availability

Overall Workload (Team Leaders)

Team Leader

Team

0

10

20

30

40

50

60

70

OPORD Anytime

Information Availability

Figure 22. Overall workload experience of the team leaders.

The results of the analysis of the overall workload scores of team members are shown in

Table 13. As indicated, the analysis revealed a significant effect of information management

(F[1, 56] = 8.210; p < .01). As illustrated in Figure 23, this latter finding suggests that team

member perceptions of workload were significantly higher when they provided support to the

team leader in managing information.
31

Table 13. ANOVA results of overall workload (team members)

______________________________________________________________________________

Source SS df MS F p

______________________________________________________________________________

Team 7320.033 7 1045.719 7.842 0.000

Team Member 13559.13 16 847.446 6.355 0.000

Availability 17.585 1 17.585 0.132 0.718

Management 1094.813 1 1094.813 8.21 0.006

Availability*Management 37.588 1 37.588 0.282 0.598

Order 601.831 3 200.61 1.504 0.223

Error 7467.473 56 133.348

______________________________________________________________________________

0

5

10

15

20

25

30

35

40

45

50

Workload 

Ratings 

(Weighted)

Team Leader Team

Information Management

Overall Workload (Team Members)

OPORD

Anytime

0

5

10

15

20

25

30

35

40

45

50

Team Leader Team

Information Management

Figure 23. Main effect of information management on the overall workload experience of team

members.

5. Discussion

Advances in communications and weapons technologies have increased the complexity of

modern warfare and the decisions the soldier must make to successfully accomplish his mission.

Although new sensor and display technologies offer to enhance soldier performance by

providing him with more information about the battlefield, it is feared that such increases can
32

lead to cognitive overload. There are also concerns that increases in the quantity of information

and the displays upon which this information is presented may compete for the soldier's

attention, reduce his awareness of the situation immediately around him, and conflict with his

performance of other critical tasks (National Research Council, 1997).

The primary objective of this field study was to examine the effects of information availability

and information management on SA and mission performance of dismounted fire teams. It was

hypothesized that the availability of information to team leaders on an HMD would enhance their

ability to recall information about the battlefield and their global SA by increasing the frequency

of information review. Navigational efficiency was also expected to improve as a function of the

frequency of updates of team position. On the other hand, the attentional demands imposed on

team leaders when they view information presented on the HMD were expected to reduce their

ability to detect wooden silhouettes of personnel that had been positioned along the course. Local

SA of the team as a whole, however, was not expected to degrade.

The results of the study indicated that in missions in which access to information on the HMD

was limited, team leaders perceived that they expended more effort and were more frustrated.

However, in missions in which information could be accessed at any time on the HMD, team

leader awareness of the local situation, as measured by the number of targets that the team

leaders detected along the course, declined significantly. Local SA of the team as a whole was

not significantly affected by the availability of information to the team leader on the HMD or

team involvement in information management. From this, however, it should not be concluded

that the HMD used in the present study was the sole contributor to losses in local SA. In a

previous study by Glumm et al. (1998), participants claimed that the HMD was not any more

distracting than their conventional hand-held displays. Certainly, any display that obstructs or

limits the field of view can cause an object or event that occurs within the area that is obscured to

go undetected. However, there is also evidence that some objects or events that are fully visible

within the same display may also go unnoticed (Mack & Rock, 1998; Most et al., 2001). Soldier

awareness of the situation beyond the display, both locally and globally, will be affected by a

number of factors. Among these factors are the amount of time and level of attention directed to

the display. The more cognitively immersed the soldier becomes in the displayed information,

the less time and attention available for other tasks, particularly those that involve the same

mental resources. In this study, the different types of information were quickly and easily

accessed via a keypad with labeled pushbuttons, but the controller used by the future soldier will

be more complex. As the time required to access information increases along with the

complexity of the information display, less time will be available to attend to the immediate

environment.

In this study, overall workload scores of team members were found to be significantly higher in

conditions in which team members provided information management support, but team

participation in managing information was not found to produce a significant improvement in

global SA or overall mission performance.
33

Contrary to hypothesis and to previous findings of Glumm et al. (1998), the availability of

positional information on the HMD did not appear to have a significant effect on navigational

efficiency. This latter finding may be attributed to the tendency of the “point man” who preceded

the rest of the team to rely less on navigational information provided by the hand-held GPS and

more on tracking a path that had been worn in some sections of the course after successive runs.

Although performance of some mission tasks appeared to be influenced by levels of information

availability, measures of overall mission performance compiled from these data were not. Good

performance of one task may have also been offset by poor performance of another.

Differences in performance between levels of information availability on the two measures of

global SA were technically not statistically significant. Nevertheless, the reader should note that

performance of the two measures of global SA appeared to take different directions when

information was available at any time on the HMD. Threat recognition performance appeared to

increase, and the accuracy of responses to probe questions appeared to decline. This anomaly

may have been influenced by differences between the two measures of SA and by the

experimental situation.

For example, the threat recognition task required a dedicated precision when the position of the

team was tracked with respect to threats. Recognizing that the team was within a specified 20- to

50-meter range of a threat required frequent updates of team location and may have been more

sensitive to the availability of navigational information which was accessed more often than

other types of tactical data. In addition to frequent updates of team position, correct responses to

probe questions also required knowledge of other kinds of information. This information

included the types of friendly or enemy units, their positions to the left or right of the designated

path, the call signs of friendly units, and available fire support. Unless this information was

studied before or during the mission, the probability of answering the probe questions correctly

was reduced to chance. In this experiment, the teams may have spent less time and attention

studying these tactical details before the mission when they knew that during the mission,

information could be accessed at any time. During the mission, however, other task demands and

reduced opportunity to review the different types of information may have decreased the

potential for accurate recall. Although competing demands are also expected to affect

information access in the actual battlefield, it is unlikely that the soldier would neglect to study

important tactical details before the mission. Implied here is the danger of relying on information

to be available during the mission.

In summary, it cannot be concluded from the results of this study that the availability of

information on an HMD or team support in managing this information will enhance or degrade

global SA. In the battlefield, some information will need to be accessed more frequently than

other information, and reductions in the availability of information may have more of an effect

on one task than on another. The findings of this study emphasize the importance of designing

displays and controls to allow quick and easy access to mission-critical information that may
34

change frequently. Also suggested is care in the selection and analysis of measures of SA to

reliably assess the value of any proposed improvements in the system.

6. Conclusions and Recommendations

In this study, increased availability of information on an HMD significantly reduced awareness

of the local situation with no statistically significant improvement in the awareness of the

situation in the larger battlefield. These findings emphasize the importance of control-display

design in the successful exploitation of advances in information technology. More information

about the battlefield is helpful to soldiers if they can use this information to their advantage.

Increases in the quantity of information may not necessarily yield a greater awareness of the

situation in the larger battlefield. Rather, the more time and attention that soldiers dedicate to the

information display, the greater the risk of losses in soldiers’ awareness of more immediate

hazards.

Designers of tactical displays and input devices for the soldier must remain aware that the

physical and psychological stresses to which soldiers are exposed compound difficulties in the

operation of complex systems. They must recognize that the capabilities of the soldier do not

keep pace with advances in technology and that advanced technology does not always provide a

solution. If information technology is to enhance soldier performance, the research and

development community must focus on minimizing the time required for soldiers to access,

interpret, and act upon information that is critical to mission performance and survival.

In this study, the level of information management support provided to the team leaders by their

team members was not found to have a significant effect on team performance.

However, as the complexity of the battlefield increases along with the quantity and diversity of

information available to soldiers, team support in managing information will become

increasingly important to maintaining global and local SA.

However, not all team leaders are inclined to share information with their team members, nor are

all team leaders skilled in identifying team member capabilities and effectively using the

resources available within their team. Future research is needed to examine information sharing,

leader skills, and training needs to maximize management of team resources.
35

References

Card, S.K., Moran, T.P, & Newell, A. (1983). The model human processor. In K.R. Boff, L.

Kaufman, & Thomas, J.P. (Eds.), Handbook of Perception and Human Performance, 45, 1-

35. New York: John Wiley and Sons.

Carpenter, S. (2001, April). Sights unseen. Monitor on Psychology, 54-55.

Endsley, M.R. (1988). Design and evaluation for situation awareness enhancement. Proceedings

of the Human Factors 32nd Annual Meeting, 1, 97-101.

Glumm, M.M., Branscome, T.A, Patton, D.J., Mullins, L.A., & Burton, P.A. (1999). The effects

of an auditory versus a visual presentation of information on soldier performance (ARL-TR1992). Aberdeen Proving Ground, MD: U.S. Army Research Laboratory.

Glumm, M.M., Marshak, W.P., Branscome, T.A, Wesler, M.M., Patton, D.J., & Mullins, L.A.

(1998). A comparison of soldier performance using current navigation equipment with

information integrated on a helmet-mounted display (ARL-TR-1604). Aberdeen Proving

Ground, MD: U.S. Army Research Laboratory.

Mack, A. & Rock, I. (1998). Inattentional blindness. Cambridge, MA: MIT Press.

Most, S.B, Simons, D.J., Scholl, B.J., Jimenez, R., Clifford, E., & Chabris, C.F. (2001). How not

to be seen: The contribution of similarity and selective ignoring to sustained inattentional

blindness. Psychological Science, 12(1), 9-17.

National Research Council (1997). Tactical display for soldiers: Human factors considerations.

Washington, DC: National Academy Press.

Van Cott, H.P., & Warrick, M.J. (1972). Man as a system component. In H.P. Van Cott & R.G.

Kinkade (Eds.), Human engineering guide to equipment design (Rev. ed.). Washington, DC:

Government Printing Office.

Wickens, C.D. (1984). Engineering psychology and human performance. Columbus, OH: Bell

& Howell.
36

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37

Appendix A: Survey and Results

Demographic Questionnaire

Instructions: Please answer each of the following questions. All the information that you

provide will remain strictly confidential. Neither you nor your unit will be identified in any

report of the results of this questionnaire.

Company/Unit: __________________ Location: __________________

Rank: _________

Age: ______ years

Military Occupational Specialty (MOS): ____________

Time in Service: ________years ______months

Time in MOS: ________years ______months

Training (Please check all that apply)

PLDC [ ]

BNCOC [ ]

ANCOC [ ]

Battle Staff [ ]

Other (Please specify) ____________

____________

____________

Positions Held (Check all that apply):

Rifleman [ ] Fire team leader [ ] Operations NCO [ ]

Automatic rifleman [ ] Ammo chief [ ] Assistant ops NCO [ ]

Machine gunner [ ] Squad leader [ ] Liaison NCO [ ]

Dragon/Javelin Gunner [ ] Platoon sergeant [ ] Intelligence NCO [ ]

Grenadier [ ] Team leader [ ] First sergeant [ ]

 Other (Please

 specify): ________

 ________
38

Combat Experience

Geographic Area Duration of Tour Did you see combat? If “Yes”

(Check all that apply) (Circle either Yes or No) Duty Position During Combat

Granada [ ] _____years ____months Yes No ______________

Somalia [ ] _____years ____months Yes No ______________

Panama [ ] _____years ____months Yes No ______________

Kuwait [ ] _____years ____months Yes No ______________

Iraq [ ] _____years ____months Yes No ______________

Bosnia [ ] _____years ____months Yes No ______________

Haiti [ ] _____years ____months Yes No ______________

Other (Please specify)

____________ _____years ____months Yes No ______________

____________ _____years ____months Yes No ______________

____________ _____years ____months Yes No ______________
What is the purpose of this questionnaire?

In the future battlefield you will have access to much more information than you have access to now. Some of this information will be

more important to your effectiveness in combat and the success of your mission than other information. Our goal is to make sure you

can easily access the information you need -- when you need it.

This questionnaire is a first step in research to measure the effects of information availability and accessibility on mission success.

We understand that your information needs depend on your mission. Therefore we have provided a description of a mission to provide

the context on which you will base your answers. It is a Movement to Contact and Attack Mission scenario that includes the likelihood

of most threats.

Instructions

This questionnaire has two parts.

In Part 1 we ask: When the mission is over, how do you know that you have been successful in performing your mission -- that is,

what are your measures of success?

We include a list of measures of success for you to choose from. We also provide space at the end of the list for you to add other

measures that you believe are important indicators of success.

First: Check ( ) all those measures that you think are indicators of mission success.

Second: Check ( ) the 10 best indicators of mission success.

Third: Rate each of these 10 indicators on how good an indicator of success it is from “good” to “excellent.”

39
In Part 2 we ask: Based on the attached mission scenario, what information do you need and when do you need to access this

information in order to achieve these measures of success?

We include a list of types of information for you to choose from. We also provide space at the end of the list for you to add other types

of information that you believe are important to achieve your 10 measures of success.

First: Check ( ) the types of information you think you need to achieve the 10 measures of success you selected in Part 1.

Second: Check ( ) the 10 types of information that are most critical to mission success -- information you just can’t do 

without if this mission is to work.

Third: Tell us when you need to receive each of these 10 types of information by checking ( ) ONE of six options.

These options are: (1) At Op Ord and only when info changes (2) At each waypoint (3) Every __ meters (4) Every __ 

minutes (5) After the mission (6) Other ______. If you choose options 3 or 4, make sure to write in the number of meters or 

minutes in the [ ___ ]. If you choose Option 6 (“Other”), make sure to write in another option.

PLEASE read the following mission scenario carefully. You may then proceed to Part 1 and then to Part 2.

40
PART 1. After the mission is over, how do you know that you have been successful in performing your mission?

(a) In Column 1, check all those measures that you believe are indicators of success. (Add other indicators, as desired,

 in the space provided at the end of the list).

(b) In Column 2, check the 10 measures that you believe are the best indicators of success.

(c) In Column 3, for each of the 10 measures you checked in Column 2, rate how good an indicator of success each is

 by placing an “X” on the scale provided.

 Average Above Excellent

 (Good) Average (Best)

Mission Success Indicators Indicator Indicator Indicator

Confident in equipment [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Confident in unit cohesion [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Maintained commo up the chain of command [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Maintained commo down the chain of command [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Followed orders [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Detected and avoided minefields [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Column

 1

 Column

 2

( 10 only)

Column

 3

41
 Average Above Excellent

 (Good) Average (Best)

Mission Success Indicators (continued) Indicator Indicator Indicator

Detected and avoided ambushes [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Detected and destroyed all enemy bunkers [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Negotiated and avoided all terrain obstacles [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Bypassed other danger areas [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Reached waypoints on time [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Quickly and accurately acquired targets [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Effectively handed off targets [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Destroyed enemy equipment [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Received adequate supporting fires [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Seized and occupied terrain [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Enemy retreated [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

All the men in my unit survived [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

No injuries in unit [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

No incidents of fratracide [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

All the enemy were destroyed [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

All the enemy were captured [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

No civilian casualties [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Did not run out of ammunition [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Column

 1

 Column

 2

( 10 only)

Column

 3

42
 Average Above Excellent

 (Good) Average (Best)

Mission Success Indicators (continued) Indicator Indicator Indicator

Did not run out of water [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Did not run out of rations [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Did not lose any equipment [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Completed mission on time [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Little to no fatigue [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Physically/mentally prepared for next mission [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Other (please specify): ______________ [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

 ______________ [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

 ______________ [ ] [ ] |_____|_____|_____|_____|_____|_____|_____|_____|

Column

 1

 Column

 2

( 10 only)

Column

 3

43
PART 2. Based on the attached mission scenario, what information items do you need and when do you need this information to

achieve these measures of success?

(a) In Column 1, check the types of information that you need to achieve the 10 measures of success you 

 selected in Part 1. (Add other types of information as desired in the space at the end of the list).

(b) In Column 2, check the 10 types of information that are most critical to mission success -- information that you could 

 NOT do without if the mission is to work.

(c) In Column 3, indicate when you need each of these 10 types of information by checking ( ) one of the six options 

 provided. (Check ONLY one option for each type of information. If you select either “Every ___ meters” or

 “Every___ minutes” be sure to write in the number of meters or minutes in the [ __ ] under that option. If you check 

 “Other” make sure to specify another option in the space provided).

Information Items

Route of march [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Terrain profile and obstacles [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

 Column

 2

(Most Critical

 10 only)

Column

 3

Column

 1

At Op Ord/ At each Every __ Every __ After Other

and only when Waypoint meters minutes mission (please

info changes specify)

44
Information Items (continued) 

Weather [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Time required to achieve waypoints [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Time and distance to objectives [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Time to complete mission [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Locations and types of targets [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Type of NBC threat [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of enemy units [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Speed and direction of movement of enemy units [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Type of enemy weapons/equipment [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of mine fields [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of enemy bunkers [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of possible ambushes [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Your unit position [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Your own position [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

 Column

 2

(Most Critical

 10 only)

Column

 3

Column

 1

At Op Ord/ At each Every __ Every __ After Other

and only when Waypoint meters minutes mission (please

info changes specify)

45
Information Items (continued)

Location of friendly units [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of adjacent friendly unit [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Speed and direction of movement of friendly units [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Available fire support (e.g., air, artillery) [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Call signs and frequencies of supporting units [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location of civilians [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Current ammunition status of your element [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Current water status of your element [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Current rations status of your element [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Location and time of next resupply [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Unit relief/time of arrival [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Other (please specify): _________________ [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

 _________________ [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

 _________________ [ ] [ ] [ ] [ ] [ ___ ] [ ___ ] [ ] ____

Thank you!

 Column

 2

(Most Critical

 10 only)

Column

 3

Column

 1

At Op Ord/ At each Every __ Every __ After Other

and only when Waypoint meters minutes mission (please

info changes specify)

46
47

Of the 30 mission success indicators listed in the survey questionnaire, each soldier selected the

10 that he believed to be the best indicators of mission success. The number of times each

success indicator was selected was calculated, and the 10 indicators selected most often were

chosen for focus in the present study.2

Table A-1. Survey results: Mission success indicators

______________________________________________________________________________

Frequency of Selection (%)

Mission Success Indicator (N = 42)

______________________________________________________________________________

 1. Maintained communication up the chain of command .7368

 2. Did not run out of ammunition .7368

 3. All the enemy were destroyed .6842

 4. All the men in my unit survived .6842

 5. Maintained communication down the chain of command .6316

 6. Seized and occupied terrain .5789

 7. No incidents of fratricide .5263

 8. Received adequate supporting fires .5263

 9. Physically and mentally prepared for next mission .5263

10. Reached waypoints on time .4211

11. Quickly and accurately acquired targets .4211

12. Detected and destroyed all enemy bunkers .3684

13. Followed orders .3158

14. Confident in unit cohesion .2632

15. No injuries in unit .2632

16. Completed mission on time .2632

17. Confident in equipment .2105

18. Destroyed enemy equipment .2105

19. Bypassed other danger areas .1579

20. Enemy retreated .1579

21. Detected and avoided ambushes .1579

22. All the enemy were captured .1579

23. No civilian casualties .1579

24. Did not run out of water .1579

25. Did not lose any equipment .1579

26. Detected and avoided minefields .1053

27. Effectively handed off targets .1053

28. Did not run out of rations .0000

29. Negotiated and avoided all terrain obstacles 5.263E-02

30. Little to no fatigue 5.263E-02

______________________________________________________________________________

 

2Eleven (11) rather than 10 indicators were selected for the study, given that mission indicators 10 and 11 were

chosen an equal number of times.
48

Table A-2. Survey results: Information requirements

______________________________________________________________________________

Frequency of Selection (%)

Information Requirements (N = 42)

______________________________________________________________________________

 1. Call signs and frequencies of supporting units .7500

 2. Available fire support .7000

 3. Locations and types of targets .6500*

 4. Current ammunition status of your element .6000

 5. Location of possible ambushes .5500

 6. Type of enemy weapons and equipment .5500

 7. Location of enemy units .5500

 8. Type of NBC threat .5500

 9. Time to complete mission .5500

10. Location of friendly units .5000

11. Location of mine fields .5000

12. Time and distance to objectives .4500

13. Location of adjacent friendly unit .4500

14. Your own position .4000

15. Route of march .4000

16. Location and time of next resupply .3500*

17. Terrain profile and obstacles .3500*

18. Your unit position .3500

19. Location of enemy bunkers .3000*

20. Speed and direction of movement of enemy units 2500*

21. Weather .2000*

22. Time required to achieve waypoints .2000

23. Current rations status of your element .1500*

24. Speed and direction of movement of friendly units .1500*

25. Unit relief/time of arrival .1500*

26. Current water status of your element 1.000E-02*

27. Location of civilians 5.000E-01*

______________________________________________________________________________

* Information not presented
49

Table A-3. Survey results: Information access requirements

______________________________________________________________________________

Information Requirements Access Requirements

______________________________________________________________________________

 1. Call signs and frequencies of supporting units At OPORD & when info changes

 2. Available fire support At OPORD & when info changes

 3. Locations and types of targets At OPORD & when info changes

 4. Current ammunition status of your element At OPORD & when info changes, and

 at each waypoint

 5. Location of possible ambushes At OPORD & when info changes

 6. Type of enemy weapons and equipment At OPORD & when info changes

 7. Location of enemy units At OPORD & when info changes

 8. Type of NBC threat At OPORD & when info changes

 9. Time to complete mission At OPORD & when info changes

10. Location of friendly units At OPORD & when info changes

11. Location of minefields At OPORD & when info changes

12. Time and distance to objectives At OPORD & when info changes

13. Location of adjacent friendly unit At OPORD & when info changes

14. Your own position At OPORD & when info changes

15. Route of march At OPORD & when info changes

16. Location and time of next resupply At OPORD & when info changes and

 after mission

17. Terrain profile and obstacles At OPORD & when info changes

18. Your unit position At OPORD & when info changes

19. Location of enemy bunkers At OPORD & when info changes

20. Speed and direction of movement of enemy units At OPORD & when info changes

21. Weather At OPORD & when info changes

22. Time required to achieve waypoints At OPORD & when info changes

23. Current rations status of your element At OPORD & when info changes and

 after mission

24. Speed and direction of movement of friendly units At OPORD & when info changes

25. Unit relief/time of arrival At OPORD & when info changes and

 after mission

26. Current water status of your element At OPORD & when info changes and

 after mission

27. Location of civilians At OPORD & when info changes

______________________________________________________________________________
50

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51

Appendix B: Situational Self-Efficacy (SSE) Scale

SSE

On a scale from 1 to 10, how confident are you in your ability to successfully

complete your upcoming mission?

Please circle one of the numbers below.

1 2 3 4 5 6 7 8 9 10

| |

Not at all Extremely

confident confident
52

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53

Appendix C: Demographic Questionnaire

Please answer the following questions. The information you provide will be kept CONFIDENTIAL.

1. Name: __________________________________________

 Last First Middle Initial

2. Age: ___________

3. Rank: __________________

4. Military Occupational Specialty (MOS): ________________

5. Time in service: ______years ________ months

6. Time in grade: _______years ________ months

7. Time in MOS: _______years ________ months

8. Are you left- or right-handed?

Left-Handed [ ] Right-Handed [ ]

9. Do you wear eyeglasses or contacts?

Yes [ ] No [ ]

10. Have you ever worn a head- or helmet-mounted display (HMD)?

Yes [ ] No [ ]

11. How would you rate your ability to use a lensatic compass?

Excellent [ ]

Good [ ]

Neither Good nor Bad [ ]

Fair [ ]

Poor [ ]

Never used one [ ]

12. How would you rate your ability to use a hand-held Global Positioning System (GPS)?

Excellent [ ]

Good [ ]

Neither Good nor Bad [ ]
54

Fair [ ]

Poor [ ]

Never Used One [ ]

13. Generally, how would you rate your land navigation skills?

Excellent [ ]

Good [ ]

Neither Good nor Bad [ ]

Fair [ ]

Poor [ ]

14. If you were to add it up, about how much time have you spent as a fire team leader prior to

this study?

Years _____ Months _____ Other? _____

15. Prior to this study, have you worked as a team with any of the other members of the team

with whom you will be working with in this study?

Yes [ ] No [ ]

 If you answered “Yes” to Question #15, please answer Questions #15a through 15c.

a. How many members of the present team have you worked with before as a team?

 One [ ] Two [ ] Three [ ]

b. On the average, about how much time have you worked with them as a team?

Years _____ Months _____ Other? _____

c. In what capacity did you work with them?

Team Leader [ ] Team Member [ ] Both [ ]
55

Appendix D: Environmental Symptoms Questionnaire (ESQ)

ENVIRONMENTAL SYMPTOMS OUESTIONNAIRE-R

INSTRUCTIONS: Indicate whether you have any of the symptoms

below by circling the appropriate number for EACH item. Answer

all items according to how you feel RIGHT NOW. (Note: It is

possible for you to have none of the symptoms below. However,

since it is important that you read every statement, respond to

each statement individually.)

NOT AT ALL SLIGHT SOMEWHAT MODERATE QUITE A BIT EXTREME

 1. I have a headache .............0 1 2 3 4 5

 2. My head is throbbing ..........0 1 2 3 4 5

 3. I feel light headed ...........0 1 2 3 4 5

4. I feel faint ..................0 1 2 3 4 5

 5. I have ringing in my ears .....0 1 2 3 4 5

 6. It is hard to breathe .........0 1 2 3 4 5

 7. My breathing seems fast .......0 1 2 3 4 5

 8. My breathing seems irregular ..0 1 2 3 4 5

 9. I feel nauseous ...............0 1 2 3 4 5

10. I feel stomach pressure .......0 1 2 3 4 5

11. I have stomach pains ..........0 1 2 3 4 5

12. My stomach is upset ...........0 1 2 3 4 5

13. I have diarrhea ...............0 1 2 3 4 5

14. I have constipation ...........0 1 2 3 4 5

15. I have to urinate frequently ..0 1 2 3 4 5

16. My heartbeat seems fast .......0 1 2 3 4 5

17. My heart is pounding ..........0 1 2 3 4 5

18. My heartbeat seems irregular ..0 1 2 3 4 5

19. My muscles are tense ..........0 1 2 3 4 5

20. My muscles ache ...............0 1 2 3 4 5

21. I have back pains .............0 1 2 3 4 5

22. I have chest pains ............0 1 2 3 4 5

23. I feel weak ...................0 1 2 3 4 5

24. My hands feel cold ............0 1 2 3 4 5

25. I feel chilly .................0 1 2 3 4 5

26. I am shivering ................0 1 2 3 4 5
56 NOT AT ALL SLIGHT SOMEWHAT MODERATE QUITE A BIT EXTREME

27. I feel warm ...................0 1 2 3 4 5

28. My hands are sweaty ...........0 1 2 3 4 5

29. I am sweating .................0 1 2 3 4 5

30. My skin feels sensitive .......0 1 2 3 4 5

31. My eyes feels irritated .......0 1 2 3 4 5

32. My eyes are watery ............0 1 2 3 4 5

33. My vision is blurry ...........0 1 2 3 4 5

34. My nose is blocked ............0 1 2 3 4 5

35. My nose is running ............0 1 2 3 4 5

36. My nose is bleeding ...........0 1 2 3 4 5

37. My ears are blocked ...........0 1 2 3 4 5

38. My ears ache ..................0 1 2 3 4 5

39. I can't hear well .............0 1 2 3 4 5

40. My mouth is dry ...............0 1 2 3 4 5

41. My throat is sore .............0 1 2 3 4 5

42. My sense of balance is off ....0 1 2 3 4 5

43. I feel clumsy .................0 1 2 3 4 5

44. I feel tired ..................0 1 2 3 4 5

45. I feel sleepy .................0 1 2 3 4 5

46. I have trouble concentrating ..0 1 2 3 4 5

47. I have trouble remembering ....0 1 2 3 4 5

 things

48. I feel worried about something 0 1 2 3 4 5

49. I feel bored ..................0 1 2 3 4 5

50. I feel irritable ..............0 1 2 3 4 5

51. I have trouble sleeping last ..0 1 2 3 4 5

 night

52. I am happy ....................0 1 2 3 4 5

53. I feel well ...................0 1 2 3 4 5

54. My thinking is clear ..........0 1 2 3 4 5

55. I have trouble understanding ..0 1 2 3 4 5

 instructions

56. Other _______________________ .0 1 2 3 4 5
57

INSTRUCTIONS: Indicate whether you had any of the symptoms

below during the exercise you just completed by circling the

appropriate number for EACH item. Answer all items. (Note: It

is possible for you to have none of the symptoms below.

However, since it is important that you read every statement,

respond to each statement individually.) NOT AT ALL SLIGHT SOMEWHAT MODERATE QUITE A BIT EXTREME

 1. I had a headache ..............0 1 2 3 4 5

 2. My head was throbbing .........0 1 2 3 4 5

 3. I felt light headed ...........0 1 2 3 4 5

4. I felt faint ..................0 1 2 3 4 5

 5. I had ringing in my ears ......0 1 2 3 4 5

 6. It was hard to breathe ........0 1 2 3 4 5

 7. My breathing seemed fast ......0 1 2 3 4 5

 8. My breathing seemed irregular .0 1 2 3 4 5

 9. I felt nauseous ...............0 1 2 3 4 5

10. I felt stomach pressure .......0 1 2 3 4 5

11. I had stomach pains ...........0 1 2 3 4 5

12. My stomach was upset ..........0 1 2 3 4 5

13. I had diarrhea ................0 1 2 3 4 5

14. I had constipation ............0 1 2 3 4 5

15. I had to urinate frequently ...0 1 2 3 4 5

16. My heartbeat seemed fast ......0 1 2 3 4 5

17. My heart was pounding .........0 1 2 3 4 5

18. My heartbeat seemed irregular .0 1 2 3 4 5

19. My muscles were tense .........0 1 2 3 4 5

20. My muscles ached ..............0 1 2 3 4 5

21. I had back pains ..............0 1 2 3 4 5

22. I had chest pains .............0 1 2 3 4 5

23. I felt weak ...................0 1 2 3 4 5

24. My hands felt cold ............0 1 2 3 4 5

25. I felt chilly .................0 1 2 3 4 5

26. I was shivering ...............0 1 2 3 4 5

27. I felt warm ...................0 1 2 3 4 5

28. My hands were sweaty ..........0 1 2 3 4 5

29. I was sweating ................0 1 2 3 4 5

30. My skin felt sensitive ........0 1 2 3 4 5

31. My eyes felt irritated ........0 1 2 3 4 5
58 NOT AT ALL SLIGHT SOMEWHAT MODERATE QUITE A BIT EXTREME

32. My eyes were watery ...........0 1 2 3 4 5

33. My vision was blurry ..........0 1 2 3 4 5

34. My nose was blocked ...........0 1 2 3 4 5

35. My nose was running ...........0 1 2 3 4 5

36. My nose was bleeding ..........0 1 2 3 4 5

37. My ears were blocked ..........0 1 2 3 4 5

38. My ears ached .................0 1 2 3 4 5

39. I couldn't hear well ..........0 1 2 3 4 5

40. My mouth was dry ..............0 1 2 3 4 5

41. My throat was sore ............0 1 2 3 4 5

42. My sense of balance was off ...0 1 2 3 4 5

43. I felt clumsy .................0 1 2 3 4 5

44. I felt tired ..................0 1 2 3 4 5

45. I felt sleepy .................0 1 2 3 4 5

46. I had trouble concentrating ...0 1 2 3 4 5

47. I had trouble remembering .....0 1 2 3 4 5

 things

48. I felt worried about something 0 1 2 3 4 5

49. I felt bored ..................0 1 2 3 4 5

50. I felt irritable ..............0 1 2 3 4 5

51. I had trouble sleeping last ...0 1 2 3 4 5

 night

52. I was happy ...................0 1 2 3 4 5

53. I felt well ...................0 1 2 3 4 5

54. My thinking was clear .........0 1 2 3 4 5

55. I had trouble understanding ...0 1 2 3 4 5

 instructions

56. Other _______________________ .0 1 2 3 4 5
59

Appendix E: National Aeronautics and Space Administration-Task Load

Index (NASA-TLX)

RATING SCALE DEFINITIONS

______________________________________________________________________________

Title End Points Descriptions

______________________________________________________________________________

MENTAL Low/High How much mental and perceptual activity was required

DEMAND (e.g., thinking, deciding, calculating, remembering, looking,

searching, etc.)? Was the task easy or demanding, simple or

complex, exacting or forgiving?

PHYSICAL Low/High How much physical activity was required (e.g., pushing,

DEMAND pulling, turning, controlling, activating, etc.)? Was the task

easy or demanding, slow or brisk, slack or strenuous, restful

or laborious?

TEMPORAL Low/High How much time pressure did you feel due to the rate or pace

DEMAND at which the task or task elements occurred? Was the pace

slow and leisurely or rapid and frantic?

PERFORMANCE Perfect/Failure How successful do you think you were in accomplishing

the goals of the task set by the experimenter (or yourself)?

How satisfied were you with your performance in

accomplishing these goals?

EFFORT Low/High How hard did you have to work (mentally and physically)

to accomplish your level of performance?

FRUSTRATION Low/High How insecure, discouraged, irritated, stressed, and annoyed

LEVEL versus secure, gratified, content, relaxed and complacent did

you feel during the task?

______________________________________________________________________________
60

 Effort

 or

Performance

Temporal Demand

 or

 Frustration

Temporal Demand

 or

 Effort

Performance

 or

Frustration

Physical Demand

 or

 Performance

Physical Demand

 or

 Frustration

 Physical Demand

 or

Temporal Demand

Temporal Demand

 or

 Mental Demand
61

Frustration

 or

 Effort

 Performance

 or

Mental Demand

 Performance

 or

Temporal Demand

Mental Demand

 or

Physical Demand

 Frustration

 or

 Mental Demand

Mental Demand

 or

 Effort

 Effort

 or

Physical Demand
62

RATING SCALE SHEET

Low High

MENTAL DEMAND

Low High

PHYSICAL DEMAND

Low High

TEMPORAL DEMAND

Good Poor

PERFORMANCE

Low High

EFFORT

Low High

FRUSTRATION
63

Appendix F: Post-Run and Post-Test Questionnaires

Based on the mission you just completed, please answer each of the following questions by

circling the response that best represents your opinion.

Table F-1. Team member questionnaire (post run)

(a) Our team easily detected the targets in the woods.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(b) Our team always knew where we were on the course.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(c) Our team always knew where we were in relation to other units and threats.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(d) We had good communications within our team.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(e) I had just the right amount of information needed to support our team's

mission.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(f) I had just the right kinds of information needed to support our team's mission.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree
64

(g) More of the information provided to the fire team leader on the HMD should

have been provided to the team members.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(h) I am confident that our team successfully performed the mission.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

Please use the space below to add any additional comments you might have.

Thank you!
65

Based on the mission you just completed, please answer each of the following questions by

circling the response that best represents your opinion.

Table F-2. Team leader questionnaire (post run)

 (a) It was easy to navigate through the course with the information provided on the

HMD.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(b) It was easy to navigate through the course using the standard navigation

equipment.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(c) I had all the right kinds of information needed to perform my mission.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(d) I had too much information.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(e) The information on the HMD was available when I needed it.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(f) It was easy to remember the information on the HMD.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(g) It was easy to remember the information on the paper map.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree
66

 (h) I was always aware of what was going on immediately around me when I was

using the HMD.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(i) I often detected targets in the woods before my team members.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(j) I always knew where we were on the course.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(k) I always knew where we were in relation to other friendly and enemy units.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(l) I always knew where we were in relation to threats.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(m) I am confident that our team successfully performed the mission.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

Please use the space below to add any additional comments you might have.

Thank you!
67

Based on your overall experience during this field study, please answer each of the following

questions by circling the response that best represents your opinion.

Table F-3. Team leader questionnaire (post test)

(a) The paper map was easy to read.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(b) The information presented on the HMD was easy to read.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(c) It was easy to understand the information on the HMD.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(d) It was easy to understand the information on the paper map.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(e) I remained aware of what was going on immediately around me when I was

reading the HMD.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(f) I remained aware of what was going on immediately around me when I was

reading the paper map.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(g) I could read the HMD while walking.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree
68

(h) I could read the standard navigation equipment while walking.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(i) The HMD was difficult to adjust.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(j) The HMD was too heavy.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(k) The HMD caused eye strain.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(l) The HMD caused motion sickness.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(m) The HMD gave me a headache.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(n) The information provided on the HMD was well organized.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

(o) Increasing the frequency at which I could access information on the HMD

helped me perform my mission better.

 (1) (2) (3) (4) (5)

Strongly Agree Neither Agree Disagree Strongly

Agree nor Disagree Disagree

Please use the space below to add any additional comments you might have.

Thank you!
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September 2002 Final

Glumm, M.M.; Pillalamarri, R.; Brundick, F.S. (all of ARL)

U.S. Army Research Laboratory

Human Research & Engineering Directorate 

Aberdeen Proving Ground, MD 21005-5425

 

AMS Code 622716

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69

75

The Effects of Information Availability and Information Management on the Performance of 

Dismounted Military Teams

This field study examined the effects of information availability on a helmet-mounted display (HMD) and team support in 

managing this information about global and local situational awareness (SA), performance, and perceptions of workload. During 

the investigation, Marine Corps fire teams performed missions in each of four experimental conditions. These four conditions 

represented a combination of two levels of information availability and two levels of information management. The two levels of 

information availability were at the operations order and (1) when changes in the position of other units occurred, and (2) when 

changes in unit position occurred and any other time during the mission. The two levels of information management were (1) team 

leader only and (2) team leader with team support. 

In missions when access to information on the HMD was limited, team leaders perceived that they expended more effort and were 

more frustrated. However, in missions when information could be accessed on the HMD at any time, local SA of team leaders, as 

measured by the number of targets they detected along the course, decreased significantly. The analyses of performance of 

measures of global SA were technically but not statistically significant. However, the results are suggestive of the potential 

influence of information availability and information management and the need for further study. As might be expected, team 

member perceptions of workload were higher when the team provided information management support, but team participation in 

information management was not found to have a significant effect on measures of global or local SA or on overall mission 

performance.

Approved for public release; distribution is unlimited.

helmet-mounted displays situational awareness team performance

information soldier performance