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1 ~ Recommendations for Research What happens when a team or group is suddenly required to react effec- tively to a situation after a period of inactivity? Does it perform well or poorly? The many anecdotal reports and case histories of incidents in which there are abrupt shifts from low to high workload suggest that perfor- mance is, at times, seriously or dangerously degraded. But, aside from some studies of single variables such as training, sleep patterns, and stress, the research knowledge base on performance after a sudden change in workload is sparse. The ways in which the interaction of different environmental, operational, and individual variables may affect performance or how their combined impact on performance can be reduced by administrative, design, or other changes is not known well understood. The Panel on Workload Transition was charged to examine the existing knowledge base and to identify and evaluate techniques that might be used to reduce performance decrements during abrupt workload transitions. The panel was asked to pay special attention to what happens to the performance of Army tank crews during sudden increases in workload but also to con- sider its effect on teams in other situations such as nuclear power plants, commercial airliners, emergency medical services, railroad locomotives, shipboard, and disaster relief efforts. In carrying out its charge the panel examined what is known about workload and workload transitions and their performance effects, identified existing research results that could be applied now and research that needed to be done to fill gaps in knowledge and inform operational policy. A large 265
266 WORKLOAD TRANSITION number of recommendations appear throughout the report. Those consid- ered by the panel to be most important appear below. WORKLOAD Task structure is known to have a significant impact on the workload imposed during the performance of the task. Much is known about the effects of variations in rate of presentation of visual stimuli for discrete tasks or display bandwidth for control tasks; however, the effects of such factors as speed-accuracy tradeoffs, task schedules, and task duration on operator performance under different levels of workload are not well de- fined, and additional research must be performed. How effective are team members in scheduling tasks appropriately under high levels of workload during a post-transition period? During most post-transition periods there are many task demands, often with critical time constraints. When performing familiar tasks for which variations in task demands are predictable, completing some tasks ahead of schedule and developing contingency plans for others during periods of low workload can reduce workload and improve performance during later higher- workload periods. Research suggests that people are able to develop more efficient strategies if given the opportunity. But more research is needed on team workload management strategies and their effectiveness. For example, the effect of teammate cooperation when one underloaded team member takes on some of the tasks usually assigned to another team member who is currently overloaded on performance is unknown. Regardless of the specific sources of workload at any point in time, adequate training and preparation, adopting strategies and tactics most ap- propriate for the situation, effective leadership, and smooth crew coordina- tion can counteract some of the detrimental effects of imposed task de- mands. The influence of stress, fatigue, training, crew coordination, and envi- ronmental stressors may have a significant effect on operator workload in operational situations, but their relationships with operator workload is not yet known, and most theories of workload ignore them. More research is required to attempt to identify the joint effects of these factors. These same factors will also affect operator performance, and they are discussed in the following sections. Quantitative scales need to be developed to rate the attributes that can be placed on these different workload drivers for the development of predictive models of workload. Continued research and development is needed to validate global opera- tor models of human performance in complex systems. Particular efforts must be focused on modeling components of the team-communication as- pects in conjunction with the individual. To what extent does workload
RECOMMENDATIONS FOR RESEARCH 267 increase with two members because of added communications, or does it decrease because of a division of labor? Before considering automation of function, careful consideration must be given to the well-documented costs of automation. Many times, automa- tion of subsystems does not result in reduced overall workload, but rather replaces one form of workload with another (Hart and Sheridan, 1984~. Operators must continue to perform a series of activities, which may appear unrelated, and their direct involvement with and knowledge of the system are reduced, making it more difficult to detect errors or assume control of the system if the automation fails. Another serious question that remains unanswered is who should maintain authority over whether the human or the automated system retains control of the system. STRESS Although there have been many recent tragic accidents in which stress may have been a contributing factor, research on the effects of stress in complex systems is sparse. The panel recommends that the Army capitalize on information that has been obtained in environments in which realistic stressors already exist. An example would be an analysis of errors in per- formance by crews working in situations that are life-threatening to the crew itself (e.g., fire bomb disposal) versus other types of life-threatening situations (e.g., medical staff in an emergency room). A research program is needed in which stressors are not experimentally induced. Two categories of techniques may be adopted to minimize the degrad- ing effects of stress on human performance: (1) design solutions, which address the task and interface with equipment and (2) personal solutions, which address the operator (through selection strategies or training), the characteristics of the team, or both. Design principles that may minimize the degrading effects of stress include: using familiar elements and elimi- nating nonessential ones, displaying information that is directly necessary for action, highlighting, and integrating displays. In addition, emergency procedures that must be referred to on-line must be brief and succinct under circumstances in which working memory and attention span are attenuated. Furthermore, procedural instructions should avoid arbitrary symbolic cod- ing and be phrased as actions to be taken, not as prohibited actions or descriptions of the state of the system. Finally, the number of steps to be taken in following emergency procedures should be held to a minimum. Personal solutions include the adoption of strategies by the operator to minimize the degrading effects of stress. Among the most effective of these are preplanning, anticipating, and rehearsing actions to be taken under stress. Research shows that if individuals can predict, understand, have knowledge of, and have a sense of control over a stressor, they are more likely to
268 WORKLOAD TRANSITION develop successful coping strategies. It is also known, however, that sim- ply providing information is one way to reduce uncertainty and increase a person's sense of control over a situation. The panel endorses the findings and recommendations made by the Committee on Techniques for the Enhancement of Human Performance (Druckman and Swets, 1988) that cognitive approaches to stress manage- ment will probably prove the most useful in the military setting. According to Druckman and Swets (1988:125), "The implication of this approach tof providing realistic information in advance] for the military is that individu- als should be given maximum knowledge and understanding of potentially harmful situations and as much control over them as possible. This conclu- sion seems just the opposite of the accepted military philosophy of giving the individual the least amount of information necessary for a given task or situation. In a combat situation it would seem that each soldier should be given as much information as possible about his situation and that of the enemy to help him manage stress levels and maintain arousal at a useful motivational level." Good team qualities, such as trust, participation in relevant decision making, excellent communications, and a commitment to cooperation are conducive to effective team-building processes. Team building efforts, as well as environmental buffers (e.g., changes in the tank environment), can be employed to minimize communication problems and the stress-related problems associated with decision making and problem solving. To date, communication in tanks has been largely ignored. However, it appears that communication is a key component in successful team performance. There- fore, research is needed to examine the effect of stress on communications. As noted above, the environment plays an important moderating role in problems arising from communications, stress, decision making, and prob- lem solving, to name a few. Although it is impossible to remove environ- mental stress from the battlefield, tank crews can be somewhat isolated from its worst effects. It is probably not advisable to completely isolate crew members from battlefield noise, since noise in battle can contain infor- mation. In fact, the headphones currently used by tank crews probably do a good job of cutting out much of the unwanted battlefield noise. Unfortu- nately, these headphones are heavy and constricting. Along with the helmets worn by crew members, they contribute to discomfort and fatigue, both of which degrade vigilance efficiency. Therefore, we recommend that lighter, more comfortable headgear, including sound-isolating headphones, be either purchased commercially or developed. The design of the suspension of tanks isolates the crew from much higher frequency vibration. However, crew members are still subject to shock from impacts and to accelerations in all directions from the overall movement of the vehicle. None of the existing crew workstations contain
RECOMMENDATIONS FOR RESEARCH 269 any degree of shock isolation, such as could be easily obtained by mounting the crew seats on shock absorbers. None of the current crew seats contain any form of personal restraint, such as seat belts or, more appropriately, 5- point harnesses. The panel recommends that all crew positions be shock isolated and that personal restraints be provided. We believe that the elimination of temperature extremes inside the ve- hicle is a worthwhile action that can be taken with existing technology. This could be accomplished by building appropriate cooling and heating systems into armored vehicles and by providing protective clothing that can insulate crew members from climatic extremes. These steps seem to be especially necessary if crew members are to remain "buttoned up" inside their vehicles for several hours or days, as in chemical warfare scenarios. In the area of displays and controls, there seem to be several small but meaningful changes that could make the job of monitoring and controlling vehicle and mission functions easier for crew members. While we did not perform a detailed analysis of crew workstation displays and controls, cer- tainly the driver's and gunner's workstations could benefit from such an analysis and rearrangement. Likewise, the general area of radio communi- cation, including the placement and design of the radio equipment should be studied with an eye to simplification and usability. Finally, the relationships among stress (including environmental stres- sors such as heat, cold, vibration, noise, and danger), fatigue, training, and crew coordination are unknown. Additional research is needed to identify these relationships, particularly in the tank environment, and to determine their unique and joint effects on operator and team performance. SLEEP PATTERNS AND FATIGUE The most important recommendation the panel can make in this area is that, before an engagement, tank crews must have a duty schedule, and the cycle time is very important. Sleep is most effective and restorative if it can be brought into phase with the 24-hour circadian rhythm. For example, four hours on duty, eight hours off, four on, eight off is an ineffective duty schedule. Sleep schedules or length of sleep periods should be modulated according to the length of time before onset of the event. In the case of the tank crew, this event would be the beginning of battle. In addition, sleep periods should be mandated and enforced by the command structure. This is particularly important for operators who per- fo~ low-level vigilance monitoring tasks or complex cognitive tasks (i.e., tank commanders). Some research has found that a single two-hour nap, strategically placed, can significantly reduce the periodic decrements of alertness and performance that occurred during 54 hours of sleep depriva- tion (Dinges et al., 1987~.
270 WORKLOAD TRANSITION Research has found that preemptive naps should be scheduled in a stag- gered manner across time and crew members and that naps must be a mini- mum of 10 minutes in duration in order to effectively restore the decre- ments due to sleep loss. However, without additional research, the minimum nap time necessary to prevent or mitigate the degrading effects of sleep loss on performance is unknown. Countermeasures for sleep loss stimulants, increased physical activ- ity, naps, monetary incentives, diet, and intensive social contact can miti gate the deterioration of performance on the first night; however, none of these remedies are effective in overcoming impairments that occur on the second or third nights of continuous operations. The last important issue that must be addressed in this area pertains to sleep habitability in the operating environment. If the environment does not have some minimum level of comfort and darkness, the amount of peaceful sleep or rest the crew members get may not be sufficient to counteract the negative effects of sleep loss. TARGET DETECTION AND VIGILANCE Signal enhancement is a driver of vigilance performance in any task. In view of what is known with regard to the importance of signal amplitude and duration in vigilance, devices for aiding target acquisition such as ther- mal imaging or computer-assisted detection systems might be built in a manner that amplifies the intensity of such critical signals as hot spots and weapon flashes and also increases the dwell time of such signals on the crews' target acquisition displays. The sensory modality of the signal plays an important role in the qual- ity of vigilant behavior, and sensory redundant displays aid in detection efficiency. Thus, an alternative technique to pure visual monitoring would be to transfer the signal into an auditory modality. For example, it might be beneficial to attempt to take advantage of this by designing a form of radar/ sonar systems for tanks that would make use of analogous audio/visual signals. Such a system might increase overall efficiency in target acquisi- tion and reduce the powerful degrading effects of a high nontarget event rate, since these effects can be eliminated in the laboratory when subjects are permitted to search for targets by alternating their inspection between analogous auditory and visual displays. Computer assistance systems may be developed that would provide crew members with information as to the most probable times of appearance and spatial locations of targets and thus reduce the effects of both temporal and spatial uncertainty on vigilance efficiency. Given the particularly deleteri- ous effects of sleep loss on low-arousal monitoring environments, we rec
RECOMMENDATIONS FOR RESEARCH 271 ommend that special consideration be given to adequate sleep for those charged with monitoring and vigilance. Tasks that are performed in succession require more processing capac- ity than tasks that are performed simultaneously. Hence, designers should strive to provide simultaneous-type displays for target acquisition functions when possible. This might be achieved by the use of instruments that furnish crew members with immediate reference standards against which events can be compared instead of forcing them to rely upon short term memory to separate signals and noise. In order to minimize the deleterious effects of vigilance on perfor- mance, the panel recommends that the crews be instructed on the biases and nonoptimal strategies of their vigilance functions in order to optimize their response strategies. In addition, training with target cueing or with knowl- edge of results can have a beneficial effect on performance in tasks requir- ing sustained attention. Team monitoring is also a possibility for enhancing target acquisition in armor crews since Army doctrine calls for overlapping fields of inspection on the battlefield. While a few experiments have re- ported an improvement in signal detectability for teams of monitors com- pared with single monitors, other experiments have reported no team advan- tage. The effects of team monitoring are complicated by the fact that social interactions between monitors play a role in determining the effectiveness of the procedure. Furthermore, only one study (Bergum and Lehr, 1962) has examined the influence of psychophysical variables on team monitoring effectiveness. Given its potential applicability to target acquisition in ar- mored combat, the team concept warrants further investigation. GEOGRAPHIC ORIENTATION The panel recommends that efforts be made to provide armored crew personnel with accurate, possibly electronic, navigational information, capi- talizing, whenever possible, on technology (e.g., digitized terrain data bases, the Global Positioning System, and inertial navigational systems). In the design of these navigational maps, consideration should be given to the appropriate frame of reference, to the depiction of updated position infor- mation, and to the realistic depiction of terrain features. Navigational systems should also support both north-up and track-up map formats. North-up formats will facilitate mission planning and com- munications between individuals who do not share the same perspective (i.e., crews in different tanks). Track-up formats will facilitate wayfinding, locating targets, and communications between individuals who share the same perspective view of the terrain (i.e., members in the same tank crew). Finally, both planned route and current position should be displayed on the map.
272 WORKLOAD TRANSITION COMMUNICATIONS AND DECISION MAKING Communications in tanks has been largely ignored as an issue, but in other systems (i.e., aviation) it has been identified as a major human factors problem. The panel recommends that the way in which information is presented to the tank commander should be redesigned. At present, the tank commander must piece together information from auditory and visual chan- nels. This adds to the confusion and may result in missed information, resulting in poor decision making and performance. Design efforts must address the potential confusion of the source of communications under high workload resulting from the tank commander monitoring two parallel radio channels and confusing the source of communications within the tank. Recent studies of expert versus nonexpert decision making in firefighting (Klein, 1989) indicate that the decision making of experts is more rapid and less demanding of their cognitive resources. Research is needed to deter- mine if decisions using this strategy are more accurate than those employ- ing more effortful strategies. Continued research is needed regarding the effectiveness of debiasing- training personnel to understand the effects of biases and heuristics on their decisions in improving the overall quality of decision performance. Deci- sion makers in complex systems should be explicitly taught about confirma- tion bias, which describes the decision makers' tendency to seek new infor- mation that supports one's currently held hypothesis and to ignore or minimize the importance of information that may support an alternative hypothesis. If a tank commander has a preconceived hypothesis regarding the nature of enemy intentions, he may interpret ambiguous evidence as consistent with these intentions. This bias has been found in the performance of Army intelligence analysts (Tolcott et al., 1989~. Care must also be taken by the team leader to guard against following preprogrammed procedures, without monitoring the continued appropriateness of the decision and the commander must be willing to modify or abandon procedures as required. STRATEGIC TASK MANAGEMENT The panel has concluded that the research base on how well and effec- tively people manage or switch activities following a workload transition is quite sparse. While basic laboratory research suggests some facility in this switching, there is a strong need for research that identifies the speed, strengths, and limitations of activity switching in high workload/high stress environments. It is particularly important to examine the extent and preva- lence of cognitive tunnel vision (the failure to switch) in emergency situa- tions, such as the Three Mile Island incident. Such research could capital- ize well on advanced simulator capabilities, such as SIMNET, in which
RECOMMENDATIONS FOR RESEARCH 273 realisticly stressful conditions can be created, and activities can be recorded digitally. Evidence that activity switching benefits from both training and clearly distinguishable cues of what tasks are required certainly leads to recom- mendations regarding the importance of practice in emergency response (see Chapter 11) and of clear, unambiguous communications within the team regarding task assignments, as discussed in Chapter 10. The benefits of preview for task management, while not based on ex- tensive data, are nevertheless consistent with arguments presented in Chap- ter 4 regarding the benefits of providing team members with knowledge of likely future stressful conditions. Research is recommended in this domain to examine the effects of partially reliable preview. Finally, the data sug- gest that, under high levels of workload, tasks are not always rescheduled according to an optimal prioritization scheme. Research should focus on the extent to which this task rescheduling can be trained. TEAM LEADERSHIP AND CREW COORDINATION Based on evidence available to date, the panel recommends that com- plex teams should maintain their integrity over some period of time. Tank crews generally do but civil aviation crews do not, at present. High-level decision makers must consider the personalities of people within groups in addition to technical competence. Crew composition has been found to have a significant effect on performance. There are three possible solu- tions: crew resource management training, selecting out the "no stuff" operators who have been found to inhibit the development of effective commu- nications, and crew composition/creation. Consideration should be given to implementing crew resource management training in all multiperson teams after it has been demonstrated that such training would be of benefit for that environment. Research is needed to examine the factors that enhance crew compatibility and productivity, as well as the individual characteristics that predict how an individual and team will function productively. A series of related actions to assess the need for formal training in leadership and crew coordination are recommended. Additional areas for action include assessment of the social-psychological impact of automation and reduced crew complement and an investigation of the role of personal- ity factors as determinants of crew performance. The importance of the mix of personalities that comprise effective and less effective crews must be examined. Research to date suggests that effective teams have high loyalty, morale, commitment, and effective task performance. Good team qualities include effective leadership, member- ship mix, commitment/cohesion, cooperation, achievement motivation, ef- fective work methods, clarity of roles and procedures, acceptance and giv
274 WORKLOAD TRANSITION ing of suggestions and criticism, individual initiative, and adaptability. At- tempting to achieve this in the tank crews would result in more effective team performance. To date, no investigation has been carried out on the extent and nature of leadership and crew coordination problems in tank crews. A number of methodological approaches can be employed to obtain a valid representa- tion of leadership and crew coordination issues in current battle tanks; these have been addressed in Chapter 10. Considerable data have been accumu- lated in aviation on the validation and behavioral impact of crew coordina- tion training. Priority should be placed on conducting research to determine if such training is applicable to tank crews. Further research is also needed to determine the effect of complement reduction on crew interactions (both communications and performance) prior to a change in crew structure. The most viable approach would be to conduct full mission simulations with accurate video and audio recordings. TRAINING The panel wishes to stress that training is not a panacea. To enhance performance of a specific task, the more repetition that occurs, the better. And to enhance problem solving and transfer to new tasks, fewer specific repetitions are recommended along with an increase in the variety of tasks that are practiced. The panel recommends that tank crews be trained to the point of automatic processing for proceduralized tasks. To perform in an expert fashion under stress, tank commanders and crews must have a thor- ough understanding of the system. The lower-level procedural skills re- quired to respond appropriately should be automated, thus freeing attention for the unique aspects of the problem at hand, and this can make vigilance performance more resistant to the effects of environmental stress and in- creased mental workload. SIMNET allows individual crew members through battalion commanders to practice tasks and roles in as realistic, complex environment as necessary to develop the appropriate skills. The panel strongly encourages the maximum utilization of SIMNET. The technology of em- bedded training allows individuals to practice procedural tasks in the opera- tional environment, which is also beneficial. Emergency procedures ought to be more trained so that attentional tun- neling does not occur. Thus, emergency problem-solving and decision mak- ing, as well as routine proceduralized tasks, must be practiced. Initial training for emergency situations should be given under nonemergency con- ditions because learning is better in nonstressed environments. But, once learned to some degree of efficiency, those procedures should be practiced under some degree of emergency stress/high workload so that operators will better learn how to respond under those conditions.
RECOMMENDATIONS FOR RESEARCH 275 On the basis of the research findings, we recommend that emergency procedures be trained to the point of automaticity. The complexity of the system and the nature of human response under stress must be known by the trainer. For simple systems, emergency procedures should be overtrained; however, for complex systems, fault diagnosis should be taught, in which operators monitor the consequences of each step in a procedure for accurate diagnosis. Considerable benefit can be gained from applying the training programs in crew resource management, successfully validated in an aviation context, to other team environments. The training principles discussed in the pre- ceding chapters provide some practical information on how to design pro- grams to enhance soldier performance. However, as noted by Hinrichs (1976), these principles have not been adequately validated to warrant wholesale application without additional research. They do provide hypotheses ame- nable to testing. Basic and applied research are most needed in the follow- ing areas: (1) the impact of stress on task performance following varying degrees and types of training and (2) the validation of training approaches against performance in a combat-like environment. This research will pro- vide the basis for a comprehensive approach for providing training that will result in a higher probability of competent performance under emergency situations such as tank combat. REFERENCES Bergum, B.O., and D.J. Lehr 1962 Vigilance performance as a function of paired monitoring. Journal of Applied Psychology 46:341-343. Dinges, D.F., K.T. Orne, W.G. Whitehouse, and E.C. Orne 1987 Temporal placement of a nap for alertness: Contributions of circadian phase and prior wakefulness. Sleep 10:313-329. Druckman, D., and J.A. Swets, eds. 1988 Enhancing Human Performance. Washington, DC: National Academy Press. Hart, S.G., and T.B. Sheridan 1984 Pilot workload, performance, and aircraft control automation. Pp. 18.1-18.12 in Proceedings of the AGARD-Symposium on Human Factors Considerations in High Performance Aircraft Conference Proceedings No. 371. Neuilly sur Seine, France: NATO Advisory Group for Aerospace Research and Development. Hinrichs, J.R. 1976 Personnel training. Pp. 829-860 in M.D. Dunnette, ea., Handbook of Industrial and Organizational Psychology. Chicago: Rand McNally. Klein, G.A. 1989 Recognition-primed decisions. Pp. 47-92 in W. Rouse, ea., Advances in Man- Machine Systems Research, Volume 5. Greenwich, Connecticut: JAI Press. Tolcott, M.A., F.F. Marvin, and T.A. Bresdick 1989 The Confirmation Bias in Military Situation Assessment. Reston, Virginia: Deci- sion Science Consortium.