Most engineering design is performed by teams. Team formation from a pool of competent designers and engineers is an important factor in helping determine performance potential. This paper is proposes a framework that we have developed to help guide research, and highlights challenges and obstacles that must be addressed in order to improve results in team formation research. A basic framework is presented and used as a basis for reviewing past work in team formation studies. This framework is then expanded to include explicit decisions about team formation and experimental strategy. Three important aspects of the framework that are critical to obtaining significant results about team formation are discussed: experimental strategy, success measures, and the separation of team formation effects from environmental effects. Recommendations for improvement in these areas are presented.