Utilizing program theory and contribution analysis to evaluate the development of science teacher leaders

• Theory of change and contribution analysis help pinpoint elements that contribute to goals.
• Project intervention components contributed to development of science teacher leaders.
• This method allowed project design to be altered before summative results are affected.
• This method improved evaluator understanding of program intentions thereby enhancing validity.

This paper illustrates how theory of change coupled with contribution analysis assisted in delineating the role each aspect of a teacher professional development program contributed to the expected outcomes. Using a mixed methods evaluation based upon the theory of change, data was gathered on 12 teacher leaders over three years. Findings indicated that not only did the teachers continue to develop as leaders over the three year project but also that the interventions designed to provide professional development to the teachers did indeed contribute to the attainment of project outcomes. By combining stakeholders’ theory of change with contribution analysis, evaluators can develop an understanding of program intentions and design an evaluation that enhances the validity of findings.