Ergonomics
-
Randomized Controlled Trial Clinical Trial
On the utility of experiential cross-training for team decision-making under time stress.
This study investigated the effectiveness of experiential cross-training in a team context for team decision-making under time stress in a simulated naval surveillance task. It was hypothesized that teams whose members explicitly experience all team positions will perform better under time pressure due to a better shared Team Interaction Model (Cannon-Bowers et al. 1993). In addition, it was posited that experiential cross-training would reduce the negative effect of member reconfiguration that can occur in certain military situations. ⋯ During the exercise, the CT group did not achieve the level of performance of the control teams. The immediate effect of team member reconfiguration was to degrade performance significantly for the non-CT teams, but not for CT teams. The findings are discussed in terms of the multiple mental models' view of team performance (Cannon-Bowers et al. 1993) and the authors discuss the relative utility of cross-training when overall training time is fixed.
-
This paper provides a critical review of social contextual and group biases that are relevant to team decision-making in command and control situations. Motivated by the insufficient level of attention this area has received, the purpose of the paper is to provide an insight into the potential that these types of biases have to affect the decision-making of such teams. The biases considered are: false consensus, groupthink, group polarization and group escalation of commitment. ⋯ A concept unifying these biases is that of the shared mental model, but whereas false consensus emanates from social projection tendencies, the rest emanate from social influence factors. The authors also discuss the 'tricky' distinction between teams and groups and propose a revised definition for command and control team. Finally, the authors emphasize the need for future empirical research in this area to pay additional attention to the social side of cognition and the potential that social biases have to affect team decision-making.
-
Described is the cooperative work of constructing team situation awareness within two teams of a military command and control unit. Specifically discussed is how the distributed cognitive and cooperative work of decision-making of the two teams is structured. The situation enabled two different ways of distributing information within the team: one serial and one parallel. ⋯ Discussed is the interaction patterns that emerge in the respective teams and their consequences for situation assessment and situation awareness. The differences are then discussed in terms of means of sharing information. Some hypotheses for future research are also offered.
-
Clinical Trial
Standard and alternative methods of stretcher carriage: performance, human factors, and cardiorespiratory responses.
Transporting a casualty on a stretcher is a common task for medical and military personnel. Stretchers are usually carried by hand, but distributing the load to other parts of the body may have advantages. To examine alternative carriage methods, 11 soldiers walked on a treadmill at 4.8 km/h while performing two-person carries of a stretcher containing an 80-kg manikin. ⋯ Subjects preferred the hip-shoulder and LCE systems overall and for specific subjective characteristics such as comfort, ease of use and stability (p<0.01). These data indicate that moving the stretcher load from the hands and placing that load on the shoulders and/or hips results in improved performance, reduced cardiorespiratory stress and favourable subjective evaluations. Further developmental work should focus on the hip-shoulder and LCE systems.
-
This study investigated the effects of hypoxia on parallel/preattentional and serial/attentional processes in early vision, and the use of a positive-end-expiratory-pressure (PEEP) to prevent the impairment in performance. Twenty-one subjects were submitted to an 8-h hypoxia exposure in a hypobaric chamber (4500 m, 589 hPa, 22 degrees C), both with and without a 5-cm H2O PEEP. Subjects carried out a visual search task consisting of detecting a target among distractors in normoxia, in acute and in prolonged hypoxia. ⋯ Results showed that prolonged hypoxia slowed serial/attentional processing whereas parallel/preattentional processes were not impaired either by acute or by prolonged hypoxia. PEEP prevented serial/attentional processes from slowing and those effects were more clearly observed in the AMS sensitive subjects with respect to the AMS insensitive subjects. These results suggest that the slowing induced by prolonged hypoxia is specific to an early visual process that pilots the scanning of an attentional spotlight throughout the visual field.