A two group-two treatment research design is presented; it allows for the assessment of the individual and the combined effects of the two treatments. Advantages include: (1) Initial evaluation represents an estimate of the stabilities of the measurements; and (2) Observation 4 compared with the average of Observation 1 and Observation 2 tests the sequential effects of the two treatments with a control group. An example of the use of the design is found in a study that sought to measure the effects of interaction analysis (IA) training and sensitivity training (ST) on the verbal teaching behavior of pre-service teachers. The point is made that interaction analysis training, if successful, would have led teachers to use appropriate styles of teaching. A review of the research is made, and ten hypotheses relating to the effect of interaction analysis training and sensitivity training on teacher behavior are stated. Twenty-one pre-service teachers participated in simulated teaching sessions in which they taught their peers at an appropriate college level. Observational data on teaching behavior was collected. Measurement remained constant during the control period, and significant changes for both groups occurred following the IA training. Conclusions include: (1) IA training influences verbal teaching style, while ST does not; (2) Subjects used more indirect methods of teaching; and (3) Student participation increased. (CK)