Abstract Norms controlling how members deal with performance strategies were altered experimentally in small task-oriented groups. The basic task required assembly of small electrical components. In one task condition (equal information) all task-relevant information was provided to each group member; in another (unequal information) it was spread unevenly among members, requiring exchange of information for optimum group performance. In the unequal information condition, an intervention inducing explicit discussion of task performance strategies improved group performance. In the equal information condition, effectiveness was increased by an intervention that reinforced existing norms against explicit discussion of performance strategies. Spontaneous discussion of strategy did not take place in control groups for either task condition, and control groups were lowest in performance effectiveness. Measures of interaction process and of member reactions to the group were affected substantially by the experimental interventions.