A logic model depicts the theoretical or model assumptions and linkages between program elements and hypothesized intermediate and long-term out-comes. The logic model is often used as a tool by program evaluators during the design phase of the research to conceptualize and guide evaluation strategies by providing a comprehensive framework for data collection and analysis. The model assumptions are often referred to as program theory and describe the program components and rationale, the process by which the program is intended to work, and the expected outcomes of the program. The logic model encompasses the key elements of the program theory and provides a system-level map, which identifies the interrelationships of the program elements, and the internal and external factors that might influence the hypothesized outcomes.
Karuntzos, G. (2003). Logic model. In M. S. Lewis-Beck, A. Bryman, & T. F. Liao (Eds.), The Sage Encyclopedia of Social Science Research Methods (pp. 585-586). Thousand Oaks, CA: Sage Publications, Ltd..