Casey: 28 college students, 54 4-hour sessions
Cowboy: 39 Air Force officers and airmen, 22 8-hour sessions
Cobra: 40 Air Force officers and airmen, 22 8-hour sessions
Cogwheel: 33 Air Force officers and airmen, 14 4-hour sessions
Results and conclusions
The first experiment (Casey) was conducted with college students from which it was determined that culture was a large factor in team as well as individual performance. While an attempt had been made to approximate a military culture in the college student team, the researchers decided that use of actual military personnel would provide more success. Hence later experiments used exclusively servicemen.
The original experimental design was to provide a particular level of difficulty to determine how well the air-defense team was able learn the individual tasks as well as the intra-team coordination needed to be successful at the air-defense task. The research team also modified the experimental design after the results of Casey, these indicated that crews were able to learn rapidly and were able to accommodate the level of difficulty, within a few sessions, to an effective level.Beginning with Cowboy, the air-defense crews were presented with a series of sessions each of which had a higher task load than the previous session. The task load was made up of two variables, kind and number of hostile aircraft and characteristics of friendly traffic (among which the hostile aircraft were sprinkled).
In the report on these experiments co-authors Chapman, Kennedy, Newell, and Biel (1959) write that:
the four [experimental] organizations behaved like organisms. Not only did the experiments provide graphic demonstrations of how much performance difference resulted from learning, but they also showed how differently the same people used the same tools under essentially the same load conditions at different times. The structures and procedures that glued functional components together so changed that an organization was only nominally the same from day to day.