The purpose of the current study was to investigate how shared and unshared information affected team outcome in the light of nominal and real group performance. An ecological approach involved realistic dilemmas solved by 28 participants from a specific, military domain. The data collection was performed at the Uppland Regiment, S1, on conscripts at the end of their national, military training. A within-groups design was used, and data collection included performance, communication and questionnaires. Although no effects of shared/unshared information on performance were obtained, communication and questionnaire measures revealed significant differences between shared and unshared information. The lack of effects on performance due to shared and unshared information may be due to the ecological approach. In line with earlier research, no performance differences were found between nominal and real groups. The conclusion is then, that real groups do not perform better than they should, compared to individuals. Finally, benefits for the Swedish Armed Forces are discussed, and it is recommended that information sharing is considered also from a social/behavioural perspective during development of information management systems for the Armed Forces.