<p><strong>OBJECTIVE:</strong> This thesis had two purposes. The main one was to examine how mixed conditions affect a Command & Control (C²) system, particularly in terms of shared understanding, situation awareness (SA), performance and workload. Mixed conditions refer here to when subsystems of a larger C²-system differ in terms of capabilities, particularly those capabilities influencing the understanding of a situation e.g. sensors or communication, which could affect the C²-capabilities when working toward a common goal. The second purpose of this thesis was to investigate a newly developed tool for measuring shared understanding, Shared Priorities, in terms of validity and usefulness.</p><p><strong>METHOD:</strong> A number of hypotheses were constructed and investigated by a controlled experiment using a microworld, C3Fire, where two-man teams fought a simulated forest fire. The independent variable manipulated was the type of support system used. One condition used one computer interface per participant, the second was mixed conditions where one participant used the computer interface and one used a paper map, and the last condition was both participants using a paper map. Different questionnaires developed to measure SA, workload etc. was used to measure the dependent variables.</p><p><strong>RESULTS:</strong> The statistical analysis performed on the collected data showed that the performance and SA was comparatively better when both participants used the computer interface than the mixed condition, which in turn was better than when both participants used a paper map. For workload and teamwork, no differences between the mixed condition and the dual map condition were found. As for the Shared Priorities measurement, no differences were found between any of the conditions.</p><p><strong>CONCLUSION: </strong>A C²-system in which some additional capabilities are introduced for some but not all subsystems may not benefit in some regards, e.g. workload and teamwork, but could improve in others, e.g. SA and performance. A Structural Equation Model (SEM) shows that the theoretical constructs of SA, workload, teamwork and performance are related and affect each other, so that the workload of the system negatively affects the teamwork and SA, while the teamwork may affect SA positively and a high SA enables high performance. </p>

OBJECTIVE: This thesis had two purposes. The main one was to examine how mixed conditions affect a Command &amp; Control (C2) system, particularly in terms of shared understanding, situation awareness (SA), performance and workload. Mixed conditions refer here to when subsystems of a larger C2-system differ in terms of capabilities, particularly those capabilities influencing the understanding of a situation e.g. sensors or communication, which could affect the C2-capabilities when working toward a common goal. The second purpose of this thesis was to investigate a newly developed tool for measuring shared understanding, Shared Priorities, in terms of validity and usefulness. METHOD: A number of hypotheses were constructed and investigated by a controlled experiment using a microworld, C3Fire, where two-man teams fought a simulated forest fire. The independent variable manipulated was the type of support system used. One condition used one computer interface per participant, the second was mixed conditions where one participant used the computer interface and one used a paper map, and the last condition was both participants using a paper map. Different questionnaires developed to measure SA, workload etc. was used to measure the dependent variables. RESULTS: The statistical analysis performed on the collected data showed that the performance and SA was comparatively better when both participants used the computer interface than the mixed condition, which in turn was better than when both participants used a paper map. For workload and teamwork, no differences between the mixed condition and the dual map condition were found. As for the Shared Priorities measurement, no differences were found between any of the conditions. CONCLUSION: A C2-system in which some additional capabilities are introduced for some but not all subsystems may not benefit in some regards, e.g. workload and teamwork, but could improve in others, e.g. SA and performance. A Structural Equation Model (SEM) shows that the theoretical constructs of SA, workload, teamwork and performance are related and affect each other, so that the workload of the system negatively affects the teamwork and SA, while the teamwork may affect SA positively and a high SA enables high performance.