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OCR for page 265
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
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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
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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
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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
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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~.
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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
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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.
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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
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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
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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.
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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.
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Representative terms from entire chapter:
crew coordination
