The Effect of Audio and Tactile Cues on Soldier 

Decision Making and Navigation in Complex 

Simulation Scenarios 

by Douglas S. Savick, Linda R. Elliott, Orest Zubal, 

and Christopher Stachowiak 

ARL-TR-4413 April 2008 

Approved for public release; distribution is unlimited. 
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Army Research Laboratory 

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ARL-TR-4413 April 2008 

The Effect of Audio and Tactile Cues on Soldier 

Decision Making and Navigation in Complex 

Simulation Scenarios 

Douglas S. Savick, Linda R. Elliott, Orest Zubal, 

and Christopher Stachowiak 

Human Research and Engineering Directorate, ARL 

Approved for public release; distribution is unlimited. 
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14. ABSTRACT 

Human factors studies of an array of military operation roles have shown significant overloading of the visual channel during 

the execution of many Soldier tasks, such as navigation and target detection (Mitchell, Samms, Glumm, Krausman, 

Brelsford, & Garrett, 2004). The objective of this study was to assess the effectiveness of tactile and three-dimensional (3-D) 

auditory cues to reduce overall workload and response time during high-visual workload target acquisition and robot 

navigation tasks. Soldiers performed target acquisition and navigation tasks in a computer-based simulation of Army target 

acquisition and navigation of robotic resources. Within this simulation (Operation Flashpoint), the participant functioned as 

the vehicle’s commander/gunner. At pre-determined intervals, semi-autonomous robots called for help and directions. The 

call for help occurred three different ways: a) visual indication, b) 3-D audio alert, and c) tactile alert. Results indicate that 

the mean response time in the tactile condition was significantly lower than in the audio or visual conditions. There was no 

significant difference between audio and visual conditions. Ratings of the National Aeronautics and Space Administration 

Task Load Index workload were lowest for tactile and highest for the 3-D audio condition. 

15. SUBJECT TERMS

multimodal display; multiple resource theory; navigation cues; Soldier decision making; Soldier performance; tactile cues; 

tactile display 

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iii 

Contents 

List of Figures v

List of Tables v

Acknowledgments vi

1. Background 1

2. Objective 3

3. Methodology 3

3.1 Participants ......................................................................................................................3 

3.2 Instrumentation................................................................................................................3 

3.2.1 Study Location ....................................................................................................3 

3.2.2 Equipment and Software .....................................................................................4 

3.3 Target Acquisition Task ..................................................................................................5 

3.4 Robotic Vehicle Control Task.........................................................................................6 

3.4.1 Visual Presentation..............................................................................................7 

3.4.2 Auditory Presentation..........................................................................................7 

3.4.3 Tactile Presentation .............................................................................................8 

3.5 Procedures .......................................................................................................................8 

3.5.1 Training ...............................................................................................................8 

3.5.2 Experimental Design ...........................................................................................9 

4. Results 10

4.1 Participants’ Results......................................................................................................10 

4.2 Accuracy Results...........................................................................................................10 

4.3 Response Time Results .................................................................................................11 

4.4 NASA TLX Index Rating Results.................................................................................12 

4.4.1 Mental Demand .................................................................................................12 

4.4.2 Physical Demand...............................................................................................13 

4.4.3 Temporal Demand.............................................................................................13 

4.4.4 Performance.......................................................................................................14 
iv 

4.4.5 Effort .................................................................................................................14

4.4.6 Frustration .........................................................................................................15 

5. Discussion 15

6. Recommendations 16

7. References 18

Appendix A. Volunteer Agreement Affidavit 21

Appendix B. Demographic Questionnaire 21

Appendix C. Vehicles’ Paths 27

Appendix D. Command Screen 29

Appendix E. NASA TLX Rating Scale and Definitions 31

Appendix F. Results of the Demographic Questionnaire 33

Appendix G. Results of the NASA TLX Questionnaire 35

Distribution List 36 
v 

List of Figures 

Figure 1. Operator station. ............................................................................................................. 4 

Figure 2. Tactile belt...................................................................................................................... 5 

Figure 3. Operation Flashpoint screen........................................................................................... 6 

Figure 4. Map screen showing robotic vehicle courses and control buttons. ................................ 7 

List of Tables 

Table 1. Order of modality presentation...................................................................................... 10 

Table 2. General demographic results. ........................................................................................ 10 

Table 3. Mean direction accuracy by display. ............................................................................. 11 

Table 4. Mean direction accuracy by roster (Soldier).................................................................. 11 

Table 5. Mean, standard error, and confidence intervals for response time by display 

modalities.............................................................................................................................. 12 

Table 6. Pair-wise comparisons of response time by display. ..................................................... 12 

Table 7. Mean ratings for mental demand by display.................................................................. 13 

Table 8. Paired comparisons for mental demand......................................................................... 13 

Table 9. Mean ratings for physical demand by display. .............................................................. 13 

Table 10. Mean ratings for temporal demand by display. ........................................................... 13 

Table 11. Paired comparisons for temporal demand. .................................................................. 14 

Table 12. Mean ratings for performance by display.................................................................... 14 

Table 13. Mean ratings for effort by display. .............................................................................. 14 

Table 14. Paired comparisons for effort. ..................................................................................... 14 

Table 15. Mean ratings for frustration by display........................................................................ 15 

Table 16. Paired comparisons for frustration............................................................................... 15 

Table G-1. NASA TLX ratings of the different systems ............................................................. 35 
vi 

Acknowledgments 

This effort was conducted as part of the Army Technology Objective for Enhanced Unit of 

Action Maneuver Team Situational Understanding, sponsored by the U.S. Army Research 

Laboratory (ARL). 

The authors wish to thank Dave Scribner of ARL for preparing the battlefield simulation 

software for the target acquisition tasks and Rick Tauson of ARL for his careful review and 

guidance during the preparation of this report. 

Address correspondence to Douglas Savick, U.S. Army Research Laboratory, Human Research 

and Engineering Directorate, Aberdeen Proving Ground, MD 21005-5425, or send e-mail to 

savick@arl.army.mil. 
1 

1. Background 

This effort was conducted as part of the Army Technology Objective (ATO) for Enhanced Unit 

of Action Maneuver Team Situational Understanding (SU), sponsored by the U.S. Army Research 

Laboratory (ARL). The intent of the SU ATO is to demonstrate information system interfaces 

that will improve Soldier SU, decision making, and mission planning. 

Military operations now have unprecedented information flow to execute action. Although technology provides ever-increasing sources of information, there is abundant literature regarding 

limitations of human information processing and resulting error in information interpretation and 

decision making because of overload. In the military, technology that involves information fusion, 

battlefield visualization, and intelligent decision-aiding technologies addresses many of these 

issues. Still, the demand for information processing increases at all levels, from the operator to 

the commander. 

Human factors studies of an array of military operation roles have shown significant overloading 

of the visual channel during the execution of many individual and multiple tasks (Mitchell, Samms, 

Glumm, Krausman, Brelsford, & Garrett, 2004). The demand for focal visual attention diminishes 

the capacity for task sharing and attention allocation, especially in the context of unexpected 

changes and events. If other sensory modalities can be effectively used in a military environment, 

the benefit could be significant in increasing survivability, information flow, and mission achievement. 

Three-dimensional (3-D) audio cues are investigated in this study for use as direction cues to the 

operator and are compared to the use of tactile cues. The use of auditory cues in providing spatial 

information about direction or location has not been adequately explored. For the most part, 

research on spatialized audio has been focused on use in aircraft to support listeners who monitor 

multiple radio communications, allowing them to selectively attend to one message at a time when 

messages are presented in different spatial locations (McKinley, Erickson, & D’Angelow, 1994; 

Glumm, Kehring, & White, 2006, 2007). In these studies, dismounted Soldiers (Haas, 

dePontbriand, Mello, Patton, & Solounias, 2000) and helicopter pilots (Haas, Gainer, Wightman, 

Couch, & Shilling, 1997) identified and responded to multi-channel radio communications more 

quickly and accurately with 3-D audio than with existing monaural displays. In addition, spatial 

information about target location has been found to have positive effects on target acquisition 

performance and perceptions of workload. In one study, commercial airline crew members 

acquired targets faster using a 3-D audio display than did crew members using a one-earpiece 

headset; however, no significant differences were found between these auditory displays in the 

number of targets acquired (Begault, 1993). In other investigations, 3-D audio cues alone did not 

improve target localization, but when paired with visual cues, the 3-D cues resulted in improvements in time and accuracy, reduced head movement, and lower subjective ratings of workload 
2 

(McKinley et al., 1995; Tannen, 2001). Glumm, Kehring, and White (2007) reported that adding 

3-D audio and tactile cues to a visual cue resulted in faster time to slew, time to first shot, and a 

higher percentage of target hits. These studies show some promise for 3-D audio cues for direction 

cues, and therefore, in this study, 3-D audio cues are used and evaluated for effectiveness as 

direction cues in a multimodal multi-task situation. 

Tactile interfaces also provide an additional sensory channel for the receipt of information through 

vibro-tactile means. A common example is the vibration mode in cell phones and pagers. More 

complex tactile interfaces use patterns of vibratory feedback through the placement of multiple 

vibrating tactors1. Although the sense of feel is not typically used as a communication channel, 

researchers are now realizing the high potential it represents. An intuitive organization of vibrotactile stimuli can portray complex and dynamic patterns and has been shown to be effective in 

numerous situations (Van Erp, 2005). 

Tactile displays have been shown to reduce overall workload when the design of the display is 

easy to interpret, intuitive, and can convey information without diverting the user’s attention 

away from the operational task at hand. In military applications, tactile displays have provided 

improved situational awareness to operators of high performance weapon platforms and have 

improved their ability to spatially track targets and sources of information. Tactile interface 

solutions have also proved effective for pilot orientation and navigation in sea, land, and air 

(Carlander & Eriksson, 2006; Calhoun, Draper, Ruff, Fontejon, & Guilfoos, 2003; Calhoun, 

Fontejon, Draper, Ruff, & Guilfoos, 2004; Chiasson, McGrath, & Rupert, 2003; Dobbins & 

Samways, 2002, 2003; van Erp & van Veen, 2003, 2004; van Erp, Veltman, van Veen, & Oving, 

2003). Underlying principles regarding tactile display and workload have also been investigated 

in more controlled lab studies with the use of synthetic tasks (Cholewiak, Brill, & Schwab, 2004; 

Lindeman, Yanagida, Sibert, & Lavine, 2003; Moorhead, Holmes, & Furnell, 2004; Sarter, 2001, 

2002). 

Although tactile interface solutions have demonstrated effectiveness in a range of applications, 

one should not assume that effectiveness will generalize across all situations. Successful implementation of tactile displays lies first in “front end2” analyses of the operator cognitive and task 

demands. Tactile displays should be considered when other sensory channels are overwhelmed 

with information, if other channels are diminished (e.g., poor visibility, high noise, fatigue, etc.) 

(Van Erp, 2005), and as a complementary channel to visual display during multi-task and high 

workload situations (Coovert et al., 2006). A principled approach is needed to identify opportunities where tactile cues are likely to alleviate workload and enhance performance. Wickens’ 

multiple resource theory (2002) provides such guidelines for the reduction of cognitive load 

through distribution of tasks and information across various sensory channels. 

 1Direct current motors (electromechanical transducers), also called tactors, are often used for vibrotactile devices. 

2A front end analysis is the first step in a design process. 
3 

2. Objective 

The objective of this study was to assess the effectiveness of tactile and 3-D auditory cues to 

reduce overall workload and response time during high visual workload target acquisition and 

robot navigation tasks. 

3. Methodology 

3.1 Participants 

Ten male Soldiers from Fort Knox, Kentucky, agreed to participate in this study. Demographic 

data are provided in appendix A. 

3.2 Instrumentation 

Soldiers performed target acquisition and navigation tasks in a computer-based simulation of 

Army target acquisition and navigation of robotic resources, as described next. 

The National Aeronautics and Space Administration (NASA) Task Load Index (TLX) was used 

to assess the participants’ experience of workload (Hart & Staveland, 1988). This technique uses 

rating scales to assess mental, physical, and temporal demands, performance, effort, and frustration. Initially, each of these six workload factors is assigned a weight, based on the responses of 

the participant to pair-wise comparisons. In these comparisons, the six factors are presented in 15 

possible pairs, and for each pair, the participant is asked to indicate the factor that s/he perceived 

contributed most 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 have contributed most to his or her workload experience are given more 

weight in the computation of an overall workload score. 

3.2.1 Study Location 

The study was performed in an indoor laboratory space, during ideal office ventilation and lighting 

conditions. Two computers, placed at about a 90-degree angle, were running at a workspace, as 

seen in figure 1. From the chair, the participants could swivel to face one computer or the other. 
4 

Figure 1. Operator station. 

3.2.2 Equipment and Software 

The two computers used were each a Dell3 OptiPlex1

 400 with 1.7-Ghz Pentium4 4 processors and 

512 Mb of memory. The imagery was presented on two 19-inch Dell flat screen cathode ray tube 

monitors. Controls were standard Dell mice and keyboards. Sennheiser5 HD280 Pro earphones 

were used to receive auditory information. A Bluetooth6 was used to deliver information to the 

Massachusetts Institute of Technology (MIT) wireless tactile control unit (WTCU). 

The WTCU was developed at MIT under the Advanced Decision Architectures Collaborative 

Technology Alliance (ADA CTA). The tactile sensors were commercial off-the-shelf inertial 

shaker motors that used the same DC “pancake” motor as is present in cell phones. The tactors 

on the WCTU system were manufactured to vibrate at 80 Hz. Each signal consisted of one tactor 

vibrating for 500 ms. Each tactor was sealed with glue and then molded in a plastic block 18.4 

mm long, 17 mm wide, and 6 mm thick. The plastic encasement was designed to make the motor 

more robust and increase the contact area between the motor and the skin. For this experiment, the 

system was configured to be worn around the waist with eight tactors at the eight map cardinal 

point positions around the Soldiers’ waists. The control unit received wireless signals from a laptop and converted them into recognizable patterns of vibration. The tactile display was powered 

by a 9-volt battery or a rechargeable 7.2-volt lithium-ion battery. The tactile belt was fitted to each 

participant to accommodate individual waist sizes. The belt was secured under the participant’s rib 

 3

Dell and OptiPlex are trademarks of Dell Corporation. 

4

Pentium is a registered trademark of Intel Corporation. 

5Sennheiser is a trademark of Sennheiser Electronic GmbH & Co. KG. 

6The Bluetooth word mark and logo are registered trademarks owned by the Bluetooth SIG, Inc. 
5 

cage over top of the undershirt. The vibrating tactors were then placed to consistently correspond 

to compass points. 

Figure 2. Tactile belt. 

Two software packages were used during this study. The first is the war game software Operation 

Flashpoint7, Game of the Year edition. Operation Flashpoint was used in a mode where it required 

the participant to acquire and destroy enemy targets. The second software package was custom 

software, written in house at ARL to provide the stimulus and data collection for the experiment. 

The stimulus was a simulation of supervisory control of three robotic vehicles. The software recorded all time and error data to a file format easily importable to Microsoft Office Excel8 and the 

statistics software package SPSS9

. 

3.3 Target Acquisition Task 

One computer system was set up to present an interactive target acquisition and engagement task 

based on the game Operation Flashpoint. Within this war game, the participant functioned as the 

vehicle’s commander/gunner. The participant looked at the computer screen to see the area around 

the moving tank from the perspective of the turret in open-hatch mode. His task was to scan the 

terrain, using the computer mouse to pan his view, and fire at targets as they became available. 

The driving function was performed by the computer following a pre-programmed course through 

complex simulated terrain. At pre-determined intervals, the robots called for help and the operator 

responded by indicating which direction the robot was to move. The call for help occurred three 

different ways: a) visual indication, b) 3-D audio alert, and c) tactile alert. Figure 3 presents a 

 7

Operation Flashpoint is a trademark of Codemasters and Bohemia Interactive Studio. 

8Excel is a trademark of Microsoft Corporation. 

9SPSS (Statistical Package for the Social Sciences) is a registered trademark of SPSS, Inc. 
6 

sample operator screen view. The mission scenario was structured to create a high-workload 

context for operations. 

Figure 3. Operation Flashpoint screen. 

3.4 Robotic Vehicle Control Task 

A map displaying the location of three simulated robotic vehicles was presented on a second 

computer system (see figure 4). The remote vehicle paths, with identified waypoints, were 

displayed on a topographic background on the screen. As a vehicle reached a waypoint, it issued 

a request to the participant to provide directional guidance so that it could reach the next waypoint. 

For this study, vehicle movement in the reverse direction was not an objective. Commands to 

move the remote vehicle did not include the southwest (SW), south (S), and southeast (SE) 

directions. 

The participant, acting as the vehicle commander/gunner, used the topographic map to identify 

the requesting vehicle, identify the waypoint at which the requestor was situated, and determine 

the compass direction that the vehicle needed to take from its present location to reach its next 

designated waypoint. An associated screen on the topographic map was cursor activated and 

allowed the participant to specify compass travel direction and send that order to the requesting 

vehicle. 
7 

Figure 4. Map screen showing robotic vehicle courses and control buttons. 

3.4.1 Visual Presentation 

In the visual information mode, the participant was first notified that a robot needed assistance 

by an auditory message through his headphones saying “robot needs help”. He looked at the 

computer with the topographic map display and noted that one of the icons in the upper right 

corner (marked “robot selection”) was blinking. The participant hit the blinking button, assuming 

control of the robot whose course matched that icon. The course of each icon was indicated by a 

different type of line (i.e., continuous, broken, or dotted). The blinking icon indicated which robot 

was concerned, and then the participant located that particular robot. Based on the location of the 

robot on the map, the participant looked to see in which direction to turn the robot to approach the 

next waypoint. Using the “direction selection” control on the bottom left of the screen, he selected 

the direction for the robot to move to reach the next waypoint. This condition was a baseline, with 

the map information being available in all modes. 

3.4.2 Auditory Presentation 

Auditory information was presented via the Sennheiser headphones. The sounds heard in the 

experiment were pre-recorded verbal alerts spoken by a female voice played as sound (wav) files 

on the computer. The alerts were digitally pre-recorded sound files of a female talker made in a 
8 

sound-treated room. We spatialized these sound files by playing them through a 3-D VALS10

audio sound engine to make them sound as if they were occurring at different spatial locations. 

The spatialization used generic head-related transfer functions developed by the U.S. Air Force. 

The headphones were used to allow for communication between the controller and participant and 

to present auditory cues. The auditory cues were presented with the use of 3-D audio software, 

allowing the cue to be directional in a plane 360 degrees around the participant’s head. The 

participant was trained to decode the apparent orientation of the auditory source around his head 

into the desired compass direction (again, north was front, west left, east right, etc.) to be taken by 

the requesting vehicle to reach its next waypoint. Selecting the robot and entering the direction to 

the next waypoint were the same as with the preceding mode. 

3.4.3 Tactile Presentation 

Tactile information was presented by a belt-like system, shown in figure 4, that was worn by the 

participant around his waist. Instead of the verbal cue used in visual mode, the participant was 

cued that a robot needed assistance by one of the tactors on the belt vibrating. The participant was 

trained to decode location of vibration on the belt into a compass direction (north was front, west 

left, east right, etc.) that the requesting vehicle was to take to reach its next waypoint. Selecting 

the robot to control and entering the robot’s direction to the next waypoint were the same as in 

visual mode. 

3.5 Procedures 

When a prospective participant arrived at the test site, he was provided with the volunteer agreement affidavit (see appendix B), and the entire testing process was explained. Any questions he 

had were answered. 

3.5.1 Training 

After the volunteer agreement affidavit had been read and signed, training in the primary and 

secondary tasks began. The participant was familiarized with the NASA TLX and the target 

acquisition task. After the participant was comfortable with the target acquisition task, training in 

the robotic vehicle control task began. The participant was trained in the procedure for each 

display mode, tested on that mode, and trained in the next mode. 

The training was conducted for two operational tasks: a) navigation though the Operation Flashpoint war game and b) conducting a robotic navigation task. First, the participant was familiarized 

with the Operation Flashpoint war game. He was given instructions for controlling his turret, looking for targets, and firing the defensive weapon. He was allowed several practice runs until he 

indicated that he was familiar with the game controls and felt comfortable, efficient, and effective 

in using the controls. Training time was approximately 30 minutes for the basic game familiariza-

 10VALS, which stands for virtual auditory localization system, is a registered trademark of Veridian Engineering. 
9 

tion; however, if the participant requested more time for practice, he was given it. Short rest 

periods were provided between practice runs. 

The training for the robotic navigation task included three different information display conditions. 

For each modality presentation, the participant wore the earphones to alert him of a request from a 

robot to direct it to the next waypoint. Additionally, the map for each robot’s path was also present 

for each modality presentation. The participant was trained in using each modality before the 

corresponding experiment test run that used that modality. 

For training the visual phase, the sequence of events was demonstrated for the participant. He 

started the trial by engaging in the war game. While he was engaged in the war game, a call for 

guidance from one of his vehicle’s (paths) was issued in his headset. He was shown on the topographical scene screen, which included vehicle paths and the command screen (appendices C and 

D), how to identify which vehicle (path) was asking for direction, how to locate the path and 

identify at which waypoint the vehicle was located. Then he was shown how to determine which 

compass direction the vehicle was to travel to reach the next waypoint. Finally, he was shown 

how to designate the compass direction on the command screen and send that command. 

Training for the auditory phase was similar to the tactile phase. An auditory call through the 

headset for directional guidance came from one of his vehicle’s (paths). The participant was 

taught to correlate the location of an audio cue to compass points. The audio cues were twodimensional, appearing to emanate around the participant’s head without an elevation component. 

Thus, the participant used audio cues’ emanation to form and send direction commands to the 

requesting vehicle (path). Training for this phase ended when the participant and the investigator 

agreed that the participant understood the scenario and could perform effectively. 

For the tactile training phase, the tactile belt was fitted to each participant. Training began with 

the Soldier engaging in the war game. An auditory call through the headset for directional 

guidance came from one of his vehicle’s (paths). At the same time, one of the devices in his belt 

was vibrating. The participant was taught to correlate that vibrating spot with a direction of the 

compass. He then could go directly to his command screen, identify the calling vehicle (path), 

translate the belt vibration to a compass direction and send that command. Training for this phase 

concluded when the participant and the investigator agreed that the participant understood the 

scenario and could perform effectively. A short break was given before each test run began. 

The participant was also familiarized with the NASA TLX and was instructed how to answer the 

NASA TLX that was issued after each test run. Training for this phase concluded when the participant and the investigator agreed that the participant understood the scenario and could perform 

effectively. A short break was provided before the test run began. 

3.5.2 Experimental Design 

Each participant was presented with a certain modality, based on the presentation order shown in 

table 1. 
10 

Table 1. Order of modality presentation. 

Participant Number Modality Order 

1, 7 A, B, C 

2, 8 B, C, A 

3, 9 C, A, B 

 4, 10 A, C, B 

 5, B, A, C 

 6, C, B, A 

A = visual; B = auditory; C = tactile 

After the test phase was selected, one computer system’s screen presented the participant with a 

driving scene and occasional advances of “enemy” attacks. Within this scenario, the vehicle under 

control advanced, and the participant had to determine which vehicle was calling, where the vehicle 

was located, and the direction the vehicle had to take to reach its next destination point. After the 

test portion was completed, when all the vehicles arrived at their destinations, the participant was 

asked to rate the experience on the NASA TLX scale. Then he was provided with a rest before 

proceeding to the next test condition. 

4. Results 

4.1 Participants’ Results 

The general demographic data for the participants are presented in appendix A. A partial analysis 

of some of the demographic data provided the average age, time in service, and time in rank. The 

results are presented in table 2. The participants’ ages ranged from 20 to 39 years old. Their 

military experience ranged from 1 to 13 years. The group consisted of one E4 (Specialist), five 

E5s (Sergeant), and four E6s (Staff Sergeant); all were right handed and four required glasses. 

Table 2. General demographic results. 

Demographic Mean SDa

Age (years) 28.2 5.45 

Time in service (years) 7.6 4.48 

Time in Rank (years) 3.2 3.43 

SD = standard deviation 

4.2 Accuracy Results 

First, results were checked with regard to the extent that Soldiers clicked on the correct robot in 

response to requests for assistance. In fact, Soldiers consistently clicked on the correct robot, 

regardless of display condition, with a mean overall accuracy of 0.998. 

Soldiers also indicated the direction for robot movement in response to requests for assistance. In 

this decision event, Soldiers could err by (a) not responding or (b) providing the wrong direction. 
11 

Soldiers did not have to refer to SW or S directions. Again, the incident of error was very small. 

Non-responses were rare (less than 1% of total responses, evenly distributed across display conditions). Table 3 provides mean differences of total direction error by display. Tactile display had 

the highest accuracy (96% correct response), then visual (95% correct response), then audio (94%). 

More of the variance in response accuracy was attributable to differences among Soldiers, as seen 

in table 4. 

Table 3. Mean direction accuracy by display. 

Display Mean SD N 

Audio 0.94 0.23 300

Tactile 0.96 0.18 300

Visual 0.95 0.21 300

Table 4. Mean direction accuracy by roster (Soldier). 

Roster Mean SD N 

1.00 0.98 0.10 90

2.00 0.92 0.26 90

3.00 0.91 0.28 90

4.00 0.98 0.10 90

5.00 0.96 0.18 90

6.00 0.97 0.14 90

7.00 0.94 0.23 90

8.00 0.92 0.26 90

9.00 0.95 0.20 90

10.00 0.94 0.23 90

Total 0.95 0.21 900

The results of analyses of variance (ANOVAs) of response accuracy indicate no significant effect 

because of display condition (F 2, 18 = 0.31; p = 0.73) or variance among Soldiers (F 9,18 = 0.72, 

p = 0.69); however, they did indicate an interaction between display and Soldier (F 2,18 = 2.27; 

p = 0.02) so that the pattern of display effects differ for different Soldiers. 

4.3 Response Time Results 

The results of the response times during the presentation of different methodologies are shown in 

table 5. The visual display modality was the baseline condition. Contrary to expectations, adding 

the audio cue actually increased response time. Adding the tactile cues resulted in lower mean 

response times. 

Data were analyzed with univariate ANOVA, within-subjects analysis of response time by display. 

Results indicate significant differences attributable to display modality (F 2, 18 = 7.7; p = 0.004), 

differences among Soldiers, and a Display x Roster interaction. Partial η2 indicates strong effect 

size (0.46). Also, results indicate a significant effect because of differences among Soldiers (F 
12 

9,18 = 4.45, p = 0.003, partial η2 = 0.69) and a smaller but significant Display x Soldier interaction 

(F 2, 18 = 3.49; p = 0.00; partial η2 = 0.07). 

Table 5. Mean, standard error, and confidence intervals for response time by display modalities 

Display Mean Standard 95% Confidence Interval 

Error Lower Bound Upper Bound 

Visual 6.480 .113 6.259 6.702 

Audio 6.593 .113 6.371 6.815 

Tactile 5.524 .113 5.302 5.747 

Post hoc pair-wise comparisons are provided in table 6. Results indicate that the mean response 

time in the tactile condition was significantly lower than in the audio or visual conditions. There 

was no significant difference between audio and visual conditions. 

Table 6. Pair-wise comparisons of response time by display. 

95% Confidence Interval for 

Difference 

(I) Display (J) Display 

Mean 

Difference 

(I-J) 

Standard

Error Sig. Lower Bound Upper Bound

Audio Tactile 1.069(*) .160 .000 .754 1.383

Visual .113 .160 .482 -.201 .427

Tactile Audio -1.069(*) .160 .000 -1.383 -.754

Visual -.956(*) .160 .000 -1.270 -.642

Visual Audio -.113 .160 .482 -.427 .201

Tactile .956(*) .160 .000 .642 1.270

*The mean difference is significant at the .05 level. 

4.4 NASA TLX Index Rating Results 

Soldiers gave direct ratings of mental demand, physical demand, temporal demand, performance 

demand, effort, and frustration (Hart & Staveland, 1988). Definitions for these aspects provided 

to Soldiers are provided in appendix E. Comparisons were made independently for each aspect 

of workload (e.g., mental demand, physical demand, temporal demand, performance, and effort). 

Ratings were analyzed with a repeated measures ANOVA. 

4.4.1 Mental Demand 

Mean ratings of mental demand are provided in table 7. Ratings were lowest for tactile and highest 

for the audio condition. ANOVA results indicate that differences among display conditions were 

significant (F 2, 18 = 7.56; p = 0.004; partial η2

 = 0.4567). Results of paired comparisons are 

provided in table 8. Using Holmes Bonferonni criteria for post hoc comparisons, we see that the 

audio condition is significantly lower than tactile. However, there was no significant difference 

between visual and other conditions. 
13 

Table 7. Mean ratings for mental demand by display. 

 Mean SD N 

Visual 5.20 2.75 10 

Audio 6.55 1.92 10 

Tactile 3.80 1.96 10 

Table 8. Paired comparisons for mental demand. 

Mental Demand t df Sig. (2-tailed) 

Visual versus Audio -2.419 9 .039 

Audio versus Tactile 3.884 9 .004 

Visual versus Tactile 1.688 9 .126 

4.4.2 Physical Demand 

Table 9 provides mean ratings for physical demand. A repeated measures ANOVA shows that 

differences are not significant (F 2, 18 = 0.22; p = 0.80; partial η2 = 0.02). 

Table 9. Mean ratings for physical demand by display. 

 Mean SD N 

Visual 2.95 3.18 10

Audio 3.15 2.82 10

Tactile 2.65 2.26 10

4.4.3 Temporal Demand 

Table 10 provides mean ratings for temporal demand. Ratings were lowest for tactile condition 

and highest for audio condition. These differences were found to be significant (F 2, 18 = 5.09; 

p = 0.02; η = 0.36). Results of paired comparisons are provided in table 11. Using Holmes Bonferonni criteria for post hoc comparisons to control for family-wise error, we see that the audio 

condition is significantly lower than the tactile condition. However, there was no significant 

difference between visual and other conditions. 

Table 10. Mean ratings for temporal demand by display. 

 Mean SD N 

Visual 4.85 2.57 10

Audio 5.55 1.96 10

Tactile 3.30 1.82 10
14 

Table 11. Paired comparisons for temporal demand. 

Temporal Demand t df Sig. (2-tailed) 

Visual versus Audio -1.326 9 .218 

Audio versus Tactile 3.126 9 .012 

Visual versus Tactile 1.774 9 .110 

4.4.4 Performance 

Performance is not a rating of workload demand per se; rather, it reflects a self-assessment of 

performance (see appendix E for definitions). Here, ratings were highest for the tactile condition 

and lowest for the visual. ANOVAs indicate that these differences are not significant (F 2, 18 = 

0.52; p = 0.60; η = 0.05). 

Table 12. Mean ratings for performance by display. 

 Mean SD N 

Visual 4.70 2.54 10

Audio 5.00 2.17 10

Tactile 5.50 2.88 10

4.4.5 Effort 

Mean ratings for effort for each display condition are provided in table 13. The tactile condition 

had the lowest mean rating, while the highest mean ratings were from the audio condition. 

ANOVAs indicate that these differences were significant (F 2, 18 = 4.15; p = 0.03; η = 0.316). 

Paired comparisons show (table 14) that differences were significant between tactile and audio; 

differences between visual and other conditions were not significant. 

Table 13. Mean ratings for effort by display. 

 Mean SD N 

Visual 5.25 2.23 10

Audio 5.95 2.25 10

Tactile 3.75 2.15 10

Table 14. Paired comparisons for effort. 

Effort t df Sig. (2-tailed) 

Visual versus Audio -1.313 9 .222 

Audio versus Tactile 2.659 9 .026 

Visual versus Tactile 1.622 9 .139 
15 

4.4.6 Frustration 

Mean ratings for frustration for each display condition are provided in table 15. The tactile 

condition had the lowest mean rating, while highest mean ratings were from the visual condition. 

ANOVAs indicate that these differences were significant (F 2, 18 = 4.57; p = 0.025; η = 0.337). 

Paired comparisons show (table 16) that differences were significant between tactile and audio; 

differences between visual and other conditions were not significant. 

Table 15. Mean ratings for frustration by display. 

 Mean SD N 

Visual 5.25 2.23 10

Audio 5.95 2.25 10

Tactile 3.75 2.15 10

Table 16. Paired comparisons for frustration. 

Frustration t df Sig. (2-tailed) 

Visual versus Audio -1.313 9 .222 

Audio versus Tactile 2.659 9 .026 

Visual versus Tactile 1.622 9 .139 

5. Discussion 

This study demonstrates effectiveness of tactile cues in a complex and dynamic decision-making 

scenario. The results indicate that the addition of tactile cues to visual cues was quite effective in 

this situation, relative to the addition of audio cues and to visual cues alone. Although differences 

in operator accuracy were not significant (all conditions were associated with high accuracy), there 

was a significant interaction between display condition and individual, with regard to accuracy, so 

that some participants were more accurate with the tactile cues, while others were more accurate in 

other cue conditions. Further research is needed in order to identify and explain this moderating 

effect. 

The addition of tactile cues to the visual cues was associated with faster response times, while the 

addition of audio cues was associated with longer response times. Post hoc comparisons showed 

that the tactile (plus visual) condition was associated with faster response times than audio (plus 

visual) and the unimodal visual cue conditions. There was also a significant interaction with 

individuals, indicating that display effects can be different, depending on individual differences. 

This interaction raises the question as to which individual differences might be important moderators with regard to display effects and display design. 
16 

One possible reason for the results regarding effectiveness of 3-D audio cues may be that the 3-D 

audio system was basically “one size fits all”; 3-D audio is most effective when tailored to each 

individual. It is likely that individuals differed in the degree to which they could accurately 

perceive 3-D localizations. This could explain why the 3-D audio condition was more variable 

and less effective than other conditions. 3-D audio cues have been used effectively for target 

localization in Air Force pilot situations (Tannen, 2001) and some other target localization tasks 

with limited success (Glumm, Kehring, & White, 2007). Another limitation for 3-D audio for the 

purpose of target localization is the front-rear confusion that often occurs. The addition of tactile 

cues to 3-D audio direction cues would resolve this, as would the addition of spatial language (e.g., 

target at 1 o’clock, etc). 

The addition of tactile cues was also associated with lower ratings of workload compared to the 

addition of audio cues. Tactile cues were associated with lower mental demand, lower temporal 

demand, lower frustration, and lower effort. Within each subject, there was correspondence 

between ratings of workload and response time. However, correlations between response time and 

workload ratings, when calculated across all subjects, were not significant. This is likely because 

of the differences among subjects in how they used the workload rating scales. That is, a rating of 

“5” is likely not equivalent across different subjects; workload ratings are thus more interpretable 

when the ratings are “within person”. 

6. Recommendations 

There is a high probability that the next generation of battle command systems will create visual 

and cognitive overload in the Soldier (Mitchell et al., 2004). Several ARL studies are focused on 

the utility of tactile and/or audio displays for various Army operator roles, with promising results 

for tasks such as land navigation, covert communications, and communication alerts (Elliott, 

Redden, Krausman, Carstens, 2005). A review of these and other studies shows that 3-D audio 

and tactile cues vary in degree of effectiveness, depending on the nature of the display and the 

purpose for which it is used (e.g., alerts, communication, direction cues) (Coovert et al., 2006; 

Redden & Elliott, 2007). Recent studies indicate that multimodal displays have potential to 

enhance operator performance. One potential advantage to designing redundancy is that in case 

environmental noise or vibration masks the auditory or tactile portion of the cues or demanding 

visual tasks interfere with the operator’s ability to see a visual cue, the operator could still rely on 

an alternate modality. A study was conducted to examine the effects of alerts on platoon leader 

performance and decision making. Tactical information was presented to a platoon leader on a 

visual display. One uni-modal and two multi-modal alerts (visual, visual and auditory, visual and 

tactile) were used. Response times for the visual alert alone were 63% slower when compared to 

both the visual and auditory and visual and tactile alerts (Krausman, Pettitt, & Elliott, 2007). 
17 

This study indicates potential effectiveness of a multi-modal display design with tactile and 

visual cues and is part of an ongoing series of studies to ascertain principles of display modality 

that can be used to refine task and workload analyses, performance models, and ultimately result 

in improved displays to reduce workload and support warfighter decision making and performance. 
18 

7. References 

Begault, D. R. Head-up Auditory Displays for Traffic Collision Avoidance System Advisories: A 

Preliminary Investigation. Human Factors 1993, 35(4), 707-717. 

Byers, J. C.; Bittner, A. C., Jr.; Hill, S. G. Traditional and Raw Task Load Index (TLX) 

Correlations: Are Paired Comparisons Necessary? In A. Mital (Ed.), Advances in industrial 

ergonomics and safety I, London: Taylor & Francis, 1989. 

Calhoun, G. L.; Draper, M. H.; Ruff, H. A.; Fontejon, J. V.; Guilfoos, B. J. Evaluation of Tactile 

Alerts for Control Station Operation. In Proceedings of the Human Factors and Ergonomics 

Society 47th Annual Meeting (pp. 2118-2122), Human Factors and Ergonomics Society: Santa 

Monica, CA, 2003. 

Calhoun, G. L.; Fontejon, J. V.; Draper, M. H.; Ruff, H. A.; Guilfoos, B. J. Tactile Versus Aural 

Redundant Alert Cues for UAV Control Applications. In Proceedings of the Human Factors 

and Ergonomics Society 48th Annual Meeting (pp. 137-141). Santa Monica, CA: Human 

Factors and Ergonomics Society, 2004. 

Carlander, O.; Eriksson, L. Uni- and Bimodal Threat Cueing With Vibrotactile and 3D audio 

Technologies in a Combat Vehicle. Paper to be presented at the 2006 Annual Conference of 

the Human Factors and Ergononics Society, San Francisco, CA, 2006. 

Chiasson, J.; McGrath, B. J.; Rupert, A. H. Enhanced Situation Awareness in Sea, Air, and Land 

Environments; ADP013874; Naval Aerospace Medical Research Lab: Pensacola, FL, 2003. 

Cholewiak, R. W.; Brill, J. C.; Schwab, A. Vibrotactile Localization on the Abdomen: Effects of 

Place and Space. Perception & Psychophysics 2004, 66 (6), 970-987. 

Coovert, M.; Gray, A.; Tolentino, A.; Jagusztyn, N.; Stilson, F.; Klein, R.; Willis, T.; Rossi, M.; 

Redden, E.; Elliott, L. Guiding Principles for Tactile Technology: Implications from Theory 

and Empirical Findings. Proceedings of the 2006 Human Factors and Ergonomics Society, 

October, San Francisco, 2006. 

Dobbins, T.; Samways, S. The Use of Tactile Navigation Cues in High-Speed Craft Operations. 

Proceedings of the RINA conference on high speed craft: technology and operation. Pp. 13-

20. London: The royal Institution of Naval Architects, 2002. 

Dobbins, T.; Samways, S. The Use of Tactile Navigation Displays for the Reduction of 

Disorientation in Maritime Environments. Qintiq Ltd Hants (United Kingdom) Centre for 

Human Sciences, 2003. 
19 

Elliott, L. R.; Redden, E.; Krausman, A.; Carstens, C. Multi-Modal Displays to Support Army 

Infantry Decisionmaking and Performance. Proceedings of the 2005 International Conference 

on Naturalistic Decisionmaking, June 2005, Amsterdam, NL, 2005. 

Glumm, M. M.; Kehring, K. L.; White, T. L. Effects of Tactile, Visual, and Auditory Cues About 

Threat Location on Target Acquisition and Attention to Visual and Auditory Communications; 

ARL-TR-3863; U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, 2006. 

Glumm, M. M.; Kehring, K. L.; White, T. L. Effects of Tactile, Visual, and Auditory Cues About 

Threat Location on Target Acquisition and Attention to Visual and Auditory Communications; 

ARL-TR-4074 U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, 2006. 

Haas, E.; dePontbriand, R.; Mello, R.; Patton, J.; Solounias, A. The Effect of Auditory display 

Type and Physical Load on Message Intelligibility for the Dismounted Soldier. Proceedings 

of the Human Factors and Ergonomics Society 44th Annual Meeting, 706 - 709, San Diego, 

CA, 2000. 

Haas, E.; Gainer, C.; Wightman, D.; Couch, M.; Shilling, R. Enhancing System Safety With 3-D 

Audio Systems. Proceedings of the Human Factors and Ergonomics Society 41st Annual 

Meeting, 868-872, Albuquerque, NM, 1997. 

Hart, S.; Staveland, L. Development of NASA-TLX (Task Load Index): Results of Empirical and 

Theoretical Research. In P.A. Hancock & N. Meshkati (Eds.). Human Mental Workload. 

Amsterdam, The Netherlands: Elsevier, 1988. 

Krausman, A.S.; Pettitt, R.A.; Elliott, L.R. Efffects of Redundant Alerts on Platoon Leader 

Performance and Decision Making; ARL-TR-3999; U.S. Army Research Laboratory: 

Aberdeen Proving Ground, MD, April 2007. 

Lindeman, R.; Yanagida, Y.; Sibert, J.; Lavine, R. Effective Vibrotactile Cueing in a Visual 

Search Task. Proceedings of the Ninth IFIP TC13 International Conference on HumanComputer Interaction (INTERACT 2003), pp 89-96, Zuerick, Switzerland, Sep 1-5, 2003. 

McKinley, R. L.; Erickson, M. A.; D’Angelo, W. R. 3-Dimensional Auditory Displays: 

Development, Applications, and Performance. Aviation, Space, and Environmental Medicine

1994, 5, A31–A38. 

McKinley, R. L.; D’Angelo, W. R.; Haas, M. W.; Perrot, D. R.; Nelson, W. T.; Hettinger, L. J.; 

Brickman, B. J. An Initial Study of the Effects of 3-Dimensional Auditory Cueing on Visual 

Target Detection. Proceedings of the Human Factors and Ergonomics Society 39th Annual 

Meeting, 119-124, Santa Monica, CA, 1995. 

Mitchell, D.K.; Samms, C.L.; Glumm, M.M., Krausman, A.S., Brelsford, M.L.; Garrett, L. 

Improved Performance Research Integration Tool (IMPRINT) Model Analyses in Support of 

the Situational Understanding as an Enabler for Unit of Action Maneuver Team Soldiers 
20 

Science and Technology Objective (STO) in Support of Future Combat Systems (FCS); ARLTR-3405; U.S. Army Research Laboratory: Aberdeen Proving Ground, MD, 2004. 

Moorhead, I.; Holmes, S.; Furnell, A. Understanding Multisensory Integration for Pilot Spatial 

Orientation. European Office of Aerospace Research and Development. Report No. 

QINETIQ/KI/CHS/TR042277, 2004. 

Raj, A. K.; Kass, S. J.; Perry, J. F. Vibrotactile Displays for Improving Spatial Awareness. 

Proceedings of the International Ergonomics Association XIV Triennial Congress / 44th 

Annual Meeting of the Human Factors and Ergonomics Society 2000, (1), 181-184. 

Redden, E.; Elliott, L. Research-Based Display Design Guidelines for Vehicle Crewman and 

Ground Warrior Interfaces, Which Enhance Situational Understanding and Decision Cycle 

Performance; ARL-TR-4231; U.S. Army Research Laboratory: Aberdeen Proving Ground, 

MD, August 2007. 

Sarter, N. Human Technology Interface: Multimodal Communication in Support of 

Coordinative Functions in Human-Machine Teams. Journal of Human Performance in 

Extreme Environments 2001, 5 (2) 50-54. 

Sarter, N. Multimodal Information Presentation in Support of Human-Automation 

Communication and Coordination. In E. Salas (Ed.) Advances in Human Performance and 

Cognitive Engineering Research, 13-36. New York: JAI Press, 2002. 

Tannen, R. Multimodal Displays for Target Localization in a Flight Test; AFRL-HE-WP-TR2001-0102; Air Force Research Laboratory: Wright Patterson Air Force Base, OH, 2001. 

Van Erp, J.B.F. Presenting Directions With a Vibrotactile Torso Display. Ergonomics 2005, 48

(3), 302-313. 

Van Erp, J.B.F.; Van Veen, H.A.H.C. A Multi-Purpose Tactile Vest for Astronauts in the 

International Space Station. Proceedings of Eurohaptics 2003, pp. 405-408. Dublin Ireland: 

Trinity College. 

Van Erp, J.B.F.; Van Veen, H.A.H.C. Vibrotactile In-Vehicle Navigation System. Transportation 

Research Part F: Human Factors 2004, 7, 247-256. 

Van Erp, J.B.F., Veltman, J. A., Van Veen, H.A.H.C.; Oving, A. B. Tactile Torso Display as 

Countermeasure to Reduce Night Vision Goggles Induced Drift. In: Spatial Disorientation 

in Military Vehicles: Causes, Consequences and Cures. RTO Meeting Proceedings 86, pp. 

49-1 - 49-8. Neuilly-sur-Seine Cedex, France: NATO RTO, 2003. 

Wickens, C. Multiple Resources and Performance Prediction. Theoretical Issues in Ergonomics 

Science 2002, 3 (2), 159-177. 
21 

Appendix A. Demographic Questionnaire 

DATE_____________ ID#______ 

DEMOGRAPHIC and EXPERIENCE FORM 

 1. Date of Birth (YYYY-MM-DD) ___________________ 

 2. Time in Service Years_________ Months__________ 

 3. Rank ____________ Time in Rank Years__________ Months _________ 

 4. Primary MOS ____________ Time in MOS Years_________ Months ________ 

 5. Secondary MOS ____________ 

 6. Duty Position/Title __________________________________________ 

 7. Time in position Years_______ Months________ 

 8. Are you (circle) Left Handed Right Handed 

 9. What is your waist size ___________? 

10. Do you wear glasses/contact Yes_____ No_____ 

11. Do you use a computer at Work_____ Home_____ Both_____ 

12. Do you play computer games Yes_____ No______ 

 If No, go to Question 13 

 12a. Estimate time playing computer games per day _________________ 

 12b. When playing, do you use Mouse_____ 

 Keyboard_____ 

 Joystick_____ 

 Other____ Specify_________________ 

13. Vehicle Experience & Crew Positions you have had (Check all that apply) 

 Commander Gunner Loader Driver 

 Bradley Fighting Vehicle [ ] [ ] [ ] [ ] 

 M1 Tank [ ] [ ] [ ] [ ] 

 Other (Please Specify)___________ [ ] [ ] [ ] [ ] 

 _________________________________ [ ] [ ] [ ] [ ] 

14. Education level (circle) GED High School Some College 

Bachelor Degree Masters Degree Ph.D. Degree Other>Specify____________ 

Any specialty civilian/military training you received_______________________ 

___________________________________________________________________________ 

___________________________________________________________________________ 
22 

INTENTIONALLY LEFT BLANK
23 

Appendix B. Volunteer Agreement Affidavit 

TID#______ 

VOLUNTEER AGREEMENT AFFIDAVIT: 

ARL-HRED Local Adaptation of DA Form 5303-R. For use of this form, see AR 70-25 or AR 40-38

The proponent for this research is: U.S. Army Research Laboratory 

Human Research and Engineering Directorate 

Aberdeen Proving Ground, MD 21005 

Authority: 

Privacy Act of 1974, 10 U.S.C. 3013, [Subject to the authority, direction, and control of the 

Secretary of Defense and subject to the provisions of chapter 6 of this title, the Secretary of 

the Army is responsible for, and has the authority necessary to conduct, all affairs of the 

Department of the Army, including the following functions: (4) Equipping (including research 

and development), 44 U.S.C. 3101 [The head of each Federal agency shall make and 

preserve records containing adequate and proper documentation of the organization, 

functions, policies, decisions, procedures, and essential transactions of the agency and 

designed to furnish the information necessary to protect the legal and financial rights of the 

Government and of persons directly affected by the agency's activities] 

Principal purpose: To document voluntary participation in the Research program. 

Routine Uses: 

The SSN and home address will be used for identification and locating purposes. 

Information derived from the project will be used for documentation, adjudication of claims, 

and mandatory reporting of medical conditions as required by law. Information may be 

furnished to Federal, State, and local agencies. 

Disclosure: 

The furnishing of your SSN and home address is mandatory and necessary to provide 

identification and to contact you if future information indicates that your health may be 

adversely affected. Failure to provide the information may preclude your voluntary 

participation in this data collection. 

Part A • Volunteer agreement affidavit for subjects in approved Department of Army research projects 

Note: Volunteers are authorized medical care for any injury or disease that is the direct result of 

participating in this project (under the provisions of AR 40-38 and AR 70-25).

Title of Research Project: 

Title: Effects of Information Presentation Modality on Soldiers’ Ability to 

Use the Information Effectively 

Human Use Protocol Log Number: ARL-- 

Principal Investigator(s): 

Orest Zubal 

US Army Research Laboratory 

Human Research and Engineering 

Directorate 

Phone: (410) 278-5841 

E-Mail: zubal@arl.army.mil 

Associate Investigator(s) 

David Scribner 

US Army Research Laboratory 

Human Research and Engineering 

Directorate 

Phone (410) 278-5983 

E-Mail dscribne@arl.army.mil 

Christopher Stachowiak 

US Army Research Laboratory 

Human Research and Engineering 

Directorate 

Phone (410) 278-4397 

E-Mail 

cstachow@arl.army.mil 

Location of Research: Aberdeen Proving Ground 

Dates of Participation: August 2004 
24 

I do hereby volunteer to participate in the research project described in the table above. I have full capacity to 

consent and have attained my 18th birthday. The implications of my voluntary participation, duration, and purpose 

of the research project, the methods and means by which it is to be conducted, and the inconveniences and hazards 

that may reasonably be expected have been explained to me. I have been given an opportunity to ask questions 

concerning this research project. Any such questions were answered to my full and complete satisfaction. Should 

any further questions arise concerning my rights or project related injury, I may contact the ARL-HRED Human 

Use Committee Chairperson at Aberdeen Proving Ground, Maryland, USA by telephone at 410-278-0612 or 

DSN 298-0612. I understand that any published data will not reveal my identity. If I choose not to participate, or 

later wish to withdraw from any portion of it, I may do so without penalty. I understand that military personnel are 

not subject to punishment under the Uniform Code of Military Justice for choosing not to take part as human 

volunteers and that no administrative sanctions can be given me for choosing not to participate. I may at any time 

during the course of the project revoke my consent and withdraw without penalty or loss of benefits. However, I 

may be required (military volunteer) or requested (civilian volunteer) to undergo certain examinations if, in the 

opinion of an attending physician, such examinations are necessary for my health and well being. 

Date of preparation of current version: 12 July 2004 

Expiration Date: 30 June 2005 Volunteer Initials_________ Administrator Initials_______ 

ID#______ 

Part B • To be completed by the Principal Investigator 

Note: Instruction for elements of the informed consent provided as detailed explanation in accordance with 

Appendix C, AR 40-38 or AR 70-25.

Purpose of the Research 

You are being invited to participate in a study designed to evaluate different techniques for presenting information 

and the effect the various presentation methods has on you performance and workload. During this study you will 

assume the role of a vehicle (Bradley Fighting vehicle, M1 Tank, etc.) and we will compare the effects giving you 

information by different methods: visual, tactile, and auditory, while you attend to a video war game and direct your 

vehicle and provide surveillance and security on the way to your destination. This study is part of the Army 

Research Laboratory’s of the Science and Technology Objective on Situational Understanding examining different 

developing technologies for presenting information to soldiers. 

Procedures 

You will be assigned a participation number and will be asked to complete a demographics questionnaire. 

You will wear your normal uniform. You may have to remove your BDU top. 

You play the role of a vehicle commander and a squad leader. You will practice playing a computer war game until 

in which you will act as the vehicles commander/gunner and provide security surveillance. You will be afforded 

several practice runs until you feel that you can operate the vehicle controls in the game. Once you’re comfortable 

playing the game you will be issued a belt that you will wear around your waist, and a set of earphones. There are 

three portions in this effort. One portion will require you to use information on a video screen and issue short orders 

using a command screen. A second portion will require you to pay attention to the vibrating belt and use its 

information to develop orders on the command screen. A third portion will present information through your 

earphones and you will develop orders on the command screen. 

You will be playing the computer game as if you were the commander of the vehicle in that game. You will also 

function as a squad leader and respond to requests from the other vehicles in your squad. As the vehicle 

commander/gunner you will have to provide tithe surveillance security for your vehicle. As you travel to your 

destination you must be vigilant to detect and destroy enemy targets that may otherwise hurt or destroy your vehicle. 

But also remember that the other three vehicles under your command in the squad are dependent on you to provide 

the direction they must travel to get to the next waypoint or get out of harm’s way. So you must attend to providing 

security for you own vehicle and quickly providing the required information so that all the vehicles in your squad 

get safely to their destinations. You will have to respond to only one of the methods (screen, belt, or earphone) 

during a test run. Before each test run you will receive practice receiving and understanding the information being 
25 

present so that you can issue the proper orders. 

After you complete each test run you will be asked to fill out a short questionnaire rating the level of effort during 

that run. 

After completing all three test runs you will be asked to fill out a final questionnaire rating the overall test. 

Total time required to complete game familiarization, training to use the different systems, performing the three test 

runs should require approximately 2 to 2 1⁄2 hours. Breaks are always available at your request. 

Benefits 

You will receive no benefits for participating in this effort, other than the personal satisfaction of support research 

efforts in the development of alternative systems for presenting information to vehicle commanders. 

Risks 

Risks associated with this effort are minimal. They are not unlike those that face computer users or computer 

gamers. Symptoms such as headaches and eye strain may be associated with extended video viewing. You may ask 

for a break any time; but, you will get a break between train sessions and test run sessions. 

Confidentiality 

All data and information obtained about you will be considered privileged and held in confidence. Photographic or 

video images of you taken during this data collection will not be identified with any of your personal information 

(name, rank, or status). All examinations will be recorded using a volunteer identifier code and a separate file with 

your consent form and the Principal Investigator will keep your assigned volunteer identifier code in a locked 

cabinet. Complete confidentiality cannot be promised, particularly if you are a military service member, because 

information bearing on your health may be required to be reported to appropriate medical or command authorities. 

In addition, applicable regulations note the possibility that the U.S. Army Medical Research and Materiel Command 

(MRMC-RCQ) officials may inspect the records. 

Date of preparation of current version: 12 July 2004 

Expiration Date: 30 June 2005 Volunteer Initials_________ Administrator Initials_______ 
26 

ID#______ 

Disposition of Volunteer Agreement Affidavit

The Principal Investigator will retain the original signed Volunteer Agreement Affidavit and forward a photocopy of 

it to the Chair of the Human Use Committee after the data collection. The test administrator will provide a copy to 

the volunteer. 

Your signature below indicates that you: (1) are at least 18 years of age, (2) have read the information on this 

form, (3) have been given the opportunity to ask questions and they have been answered to your satisfaction, 

and (4) have decided to participate based on the information provided on this form. 

Printed Name of Volunteer (First, MI., Last) 

Social Security Number (SSN) 

Date of Birth 

(Month, Day, Year) 

Permanent Address of Volunteer 

Today’s Date 

(Month, Day, Year)

Signature of Volunteer 

Signature of Administrator 

Contacts for Additional Assistance

If you have questions concerning your rights on research-related injury, or if you have any complaints about your 

treatment while participating in this research, you can contact: 

Chair, Human Use Committee OR Office of the Chief Counsel 

U.S. Army Research Laboratory U.S. Army Research Laboratory 

Human Research and Engineering Directorate 2800 Powder Mill Road 

Aberdeen Proving Ground, MD 21005 Adelphi, MD 20783-1197 

(410) 278-0612 or (DSN) 298-0612 (301) 394-1070 or (DSN) 290-1070 

Date of preparation of current version: 12 July 2004 

Expiration Date: 30 June 2005 Volunteer Initials_________ Administrator Initials_______ 
27 

Appendix C. Vehicles’ Paths 

Representation of Paths to be followed during the Training and Test Phases 

The above generic paths represent routes to be taken by three separate vehicles, the characteristics of the paths are: 

 Starting points are identified by the triangles 

 Waypoints are identified by small dots 

 Location of the vehicle is at the large dot 

 End point is at the last large “empty” dot 

The actual paths to be used in the effort will be such as to be compatible with the background topography and 

feature start and end points and ten intermediate waypoints. 
28 

INTENTIONALLY LEFT BLANK
29 

Appendix D. Command Screen 

Command Screen Available for Sending Course Direction to the Vehicle in Question 

The command screen that the participant will use to set and send the directional data to the requesting path. 

Along the left are the paths that are displayed on the separate topographic screen. The path requesting the 

directional update is highlighted by the box. 

The participant can determine the appropriate direction, using either visual, tactile, or auditory method and select the 

compass direction and activate the send button. 

N

S

W E

NW NE 

SW SE 

SEND
30 

INTENTIONALLY LEFT BLANK
31 

Appendix E. NASA TLX Rating Scale and Definitions 

 MODALITY:______________________ DATE_____________ ID#______ 

TLX Workload Scale 

Please rate your workload by putting a mark on each of the six scales at the point which matches your 

experience. 

Mental Demand 

Physical Demand

Temporal Demand 

Performance

Effort

Frustration

Good Poor 

Low High 

Low High 

Low High 

Low High 

Low High 
32 

TLX Rating Scale Definitions 

Rating Scale Title Description 

Mental Demand 

How much mental and perceptual activity was required (e.g., thinking, 

deciding, calculating, remembering, looking, searching, etc.)? Was the task 

easy or demanding, simple or complex, exacting or forgiving? 

Physical Demand 

How much physical activity was required (e.g., pushing, pulling, turning, 

controlling, activating, etc.)? Was the task easy or demanding, slow or brisk, 

slack or strenuous, restful or laborious? 

Temporal Demand 

How much time pressure did you feel due to the rate or pace at which the task 

or task elements occurred? Was the pace slow and leisurely or rapid and 

frantic? 

Performance 

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 

How hard did you have to work (mentally and physically to accomplish your 

level of performance? 

Frustration 

How insecure, discouraged, irritated, stressed and annoyed versus secure, 

gratified, content, relaxed and complacent did you feel during the task? 
33 

Appendix F. Results of the Demographic Questionnaire 

 Age SER VICE Time in Rank Time In MOS

No. DOB Date Yrs. Yrs Mo Yrs Mo Ra

nk 

Yrs Mo. MOS Yrs Mo. 

1 19781013 20050317 26 26 5 7 6 E6 2 1 19K 7 6 

2 19720928 20050318 32 32 6 11 8 E6 11 8 63M N/A N/A 

3 19730706 20050318 31 31 8 12 2 E6 4 0 63M 12 2 

4 19850213 20050318 20 20 1 1 6 E4 0 2 19D 1 6 

5 19820708 20050318 22 22 8 3 1 E5 1 1 19K 3 9 

6 19761201 20050322 28 28 3 9 2 E5 5 6 92Y 9 8 

7 19790823 20050322 25 25 7 2 6 E5 0 6 19D 1 8 

8 19761002 20050323 28 28 7 6 7 E5 1 0 11B 6 7 

9 19730828 20050324 31 31 7 12 11 E6 2 0 11B 12 11 

10 19660203 20050324 39 39 1 13 5 E5 6 0 19K N/A N/A 

 AVG 28.2 5.3 7.6 5.4 3.2 2.4 6.4 7.1 

 S.D. 5.45 2.71 4.48 3.06 3.43 3.06 4.47 2.64 

 Ranks E4 1 

 E5 5 

 E6 4 

 Second Time In Pos. Han ded Glasses 

No. MOS Duty Poss. Yrs Mo L R Waist Y N 

1 None Instructor 1 1 X 40 X 

2 4ST Drill Sgt 3 0 X 34 X 

3 None Sys Maint 12 2 X 33 X 

4 None Scout 0 2 X 36 X 

5 None TC/Instructor 0 8 X 32 X 

6 None Suply Sgt. 5 6 X 34 X 

7 None Instructor 1 8 X 34 X 

8 None Infantry 6 7 X 35 X 

9 None Inf Drl Sgt 1 0 X 34 X 

10 None TC/Instructor 6 0 X 34 X 

 AVG 3.5 3.4 34.6 

 S.D. 3.81 3.44 2.17 

 Glasses 4 6 
34 

 Use Puter Pla

y 

Gam Per Use In Play Vehicle Position 

No. Work Hom

e 

Y N Da

y 

Mous

e 

KeyB Joy Othr Brad M1 Othr C G L D 

1 X X 30 X X X X X X X 

2 X X X 120 X X X X B B/M1

3 X X 0 X X B B/M1

4 X X 0 X X 

5 X X 0 X X X X X 

6 X X X 0 N/A 

7 X X X 0 X HMMMV B/H 

8 X X 120 X X N/A 

9 X X 30 X X X A N/A 

10 X X X X X X X X 

 A Thrumaster FCS with Paddles 

 Education 

No. GED High S Some COL BS MS PHD Other 

1 X 

2 X 

3 X 

4 X 

5 X 

6 X 

7 X 

8 X 

9 X 

10 X 

No. Training Specialty 

1 HAZMAT, Instructor Course 

2 Automotive Tech 

3 None 

4 None 

5 None 

6 None 

7 None 

8 None 

9 SOTIX Course, Airborne, Air Assault, Drill Sergeant Course, ILRP course, Patrol & Advanced 

10 None 
35 

Appendix G. Results of the NASA TLX Questionnaire 

Table G-1. NASA TLX ratings of the different systems 

 

Participant 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 

Visual 

Mental 4.0 6.0 0.0 2.0 5.5 9.0 4.0 8.0 6.5 7.0 

Physical 1.0 6.5 0.0 0.5 0.0 6.0 0.0 8.5 4.5 2.5 

Temporal 5.0 8.0 5.0 0.5 4.0 5.0 1.0 8.5 6.0 5.5 

Performance 4.0 1.5 7.5 1.0 2.0 6.0 5.0 8.5 6.0 5.5 

Effort 5.0 5.0 5.0 1.0 5.5 8.0 2.5 8.5 6.0 6.0 

Frustration 2.0 3.0 5.5 0.5 4.5 5.0 0.0 9.0 5.5 5.5 

 AVG 4.5 

 S.D. 2.69 

Auditory 

Mental 5.0 9.5 4.5 5.5 6.0 9.0 4.0 8.5 6.5 7.0 

Physical 2.0 4.0 0.5 1.5 0.0 6.0 0.0 8.5 4.5 4.5 

Temporal 6.0 8.0 3.5 5.0 5.0 7.0 2.0 8.5 5.5 5.0 

Performance 3.0 4.0 7.5 1.0 5.0 6.0 4.0 8.5 6.0 5.0 

Effort 7.0 7.0 5.0 5.0 7.0 8.0 0.5 8.5 6.0 5.5 

Frustration 7.0 1.5 5.0 4.0 5.5 6.5 3.0 8.5 5.5 6.5 

 AVG 5.3 

 S.D. 2.38 

Tactile 

Mental 3.0 2.5 2.5 4.5 5.0 7.0 1.0 2.0 4.0 6.5 

Physical 3.0 2.5 0.0 4.0 0.0 6.0 0.0 2.0 3.0 6.0 

Temporal 2.0 3.0 2.5 3.5 3.5 5.0 0.0 2.0 6.0 5.5 

Performance 7.0 0.5 6.5 1.0 5.5 7.0 9.0 3.5 7.5 7.5 

Effort 2.0 4.5 2.0 5.5 3.0 7.0 1.0 1.5 4.5 6.5 

Frustration 3.0 2.0 1.5 4.5 5.0 2.5 0.0 2.0 4.0 5.0 

 AVG 3.7 

 S.D. 2.27 
36 

NO. OF 

COPIES ORGANIZATION

 1 DEFENSE TECHNICAL 

 (PDF INFORMATION CTR 

 ONLY) DTIC OCA 

 8725 JOHN J KINGMAN RD 

 STE 0944 

 FORT BELVOIR VA 22060-6218 

 1 US ARMY RSRCH DEV & ENGRG CMD 

 SYSTEMS OF SYSTEMS INTEGRATION 

 AMSRD SS T 

 6000 6TH ST STE 100 

 FORT BELVOIR VA 22060-5608 

 1 DIRECTOR 

 US ARMY RESEARCH LAB 

 IMNE ALC IMS 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

 1 DIRECTOR 

 US ARMY RESEARCH LAB 

 AMSRD ARL CI OK TL 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

 1 DIRECTOR 

 US ARMY RESEARCH LAB 

 AMSRD ARL CS OK T 

 2800 POWDER MILL RD 

 ADELPHI MD 20783-1197 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR ML J MARTIN 

 MYER CENTER RM 2D311 

 FT MONMOUTH NJ 07703-5601 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MZ A DAVISON 

 320 MANSCEN LOOP STE 115 

 FT LEONARD WOOD MO 65473 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MD T COOK 

 BLDG 5400 RM C242 

 REDSTONE ARSENAL AL 35898-7290 

 1 COMMANDANT USAADASCH 

 ATTN ATSA CD 

 ATTN AMSRD ARL HR ME DR HAWLEY 

 5800 CARTER RD 

 FT BLISS TX 79916-3802 

NO. OF 

COPIES ORGANIZATION

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MM DR V J RICE 

 BLDG 4011 RM 217 

 1750 GREELEY RD 

 FT SAM HOUSTON TX 78234-5002 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MG R SPINE 

 BUILDING 333 

 PICATINNY ARSENAL NJ 07806-5000 

 1 ARL HRED ARMC FLD ELMT 

 ATTN AMSRD ARL HR MH C BURNS 

 BLDG 1467B ROOM 336 

 THIRD AVENUE 

 FT KNOX KY 40121 

 1 ARMY RSCH LABORATORY - HRED 

 AWC FIELD ELEMENT 

 ATTN AMSRD ARL HR MJ D DURBIN 

 BLDG 4506 (DCD) RM 107 

 FT RUCKER AL 36362-5000 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MK MR J REINHART 

 10125 KINGMAN RD 

 FT BELVOIR VA 22060-5828 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MV HQ USAOTC 

 S MIDDLEBROOKS 

 91012 STATION AVE ROOM 348 

 FT HOOD TX 76544-5073 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MY M BARNES 

 2520 HEALY AVE STE 1172 BLDG 51005 

 FT HUACHUCA AZ 85613-7069 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MP D UNGVARSKY 

 POPE HALL BLDG 470 BCBL 

 806 HARRISON DR 

 FT LEAVENWORTH KS 66027-2302 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MJF J HANSBERGER 

 JFCOM JOINT EXPERIMENTATION J9 

 JOINT FUTURES LAB 

 115 LAKEVIEW PARKWAY SUITE B 

 SUFFOLK VA 23435 
37 

NO. OF 

COPIES ORGANIZATION

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MQ M R FLETCHER 

 US ARMY SBCCOM NATICK SOLDIER CTR 

 AMSRD NSC WS E BLDG 3 RM 343 

 NATICK MA 01760-5020 

 1 ARMY RSCH LABORATORY-HRED 

 ATTN AMSRD ARL HR MT J CHEN 

 12423 RESEARCH PARKWAY 

 ORLANDO FL 32826 

 1 ARMY RSCH LABORATORY-HRED 

 ATTN AMSRD ARL HR MT C KORTENHAUS 

 12350 RESEARCH PARKWAY 

 ORLANDO FL 32826 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MS C MANASCO 

 SIGNAL TOWERS BLDG 29808A RM 303 

 FORT GORDON GA 30905-5233 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MU M SINGAPORE 

 6501 E 11 MILE RD MAIL STOP 284 

 BLDG 200A 2ND FL RM 2104 

 WARREN MI 48397-5000 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MF C HERNANDEZ 

 2421 NW AUSTIN RD STE 220 

 FORT SILL OK 73503-9042 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MW L ELLIOTT 

 BLDG 4 ROOM 332 

 FT BENNING GA 31905-5400 

 1 ARMY RSCH LABORATORY - HRED 

 ATTN AMSRD ARL HR MN R SPENCER 

 DCSFDI HF 

 HQ USASOC BLDG E2929 

 FORT BRAGG NC 28310-5000 

 1 ARMY G1 

 ATTN DAPE MR B KNAPP 

 300 ARMY PENTAGON ROOM 2C489 

 WASHINGTON DC 20310-0300 

NO. OF 

COPIES ORGANIZATION

 ABERDEEN PROVING GROUND

 1 DIRECTOR 

 US ARMY RSCH LABORATORY 

 ATTN AMSRD ARL CI OK (TECH LIB) 

 BLDG 4600 

 1 DIRECTOR 

 US ARMY RSCH LABORATORY 

 ATTN AMSRD ARL CI OK TP S FOPPIANO 

 BLDG 459 

 1 DIRECTOR 

 US ARMY RSCH LABORATORY 

 ATTN AMSRD ARL HR MR F PARAGALLO 

 BLDG 459 

 2 DIRECTOR 

 US ARMY RSCH LABORATORY 

 ATTN AMSRD ARL HR MX D SAVICK 

 O ZUBAL 

 BLDG 459 

 1 DIRECTOR 

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 ATTN AMSRD ARL HR SC C STACHOWIAK 

 BLDG 463