Monday, July 03, 2023

In program evaluation a Theory of Change (TOC) is “a description and graphic illustration of the processes of how and why a desired change is expected to happen in a particular context, sometimes used interchangeably with program theory.1” 


For me a Theory of Change is a chain of outcomes where one outcome leads to another. In my last blog I defined an outcome as “What change for what group of people?” So a TOC combines outcomes into a logical order. For example, if I (what group of people?) want to lose weight (what change?), I may need to decrease my caloric intake. In order to decrease my caloric intake, I need to change my eating habits. In order to change my eating habits, I have to believe that I can control my eating habits. I also have to understand basic nutrition. So graphically it looks like this: 



This is a very simple example, but the point is that each box contains an outcome that we are trying to achieve. It is this series of outcomes that allows us to build the TOC. Sometimes TOC and Logic Model are also used interchangeably. The logic model adds the things you need and the things you do in order to achieve these outcomes. 

This particular blog is an introduction to a series of posts on building and using theories of change as you develop strategy, measure the progress of your program’s activities, and evaluate your program. We will talk about how to build a TOC at both the organizational level and the community level.  


1Thomas, Veronica and Campbell, Patricia. Evaluation in Today’s World: Respecting Diversity, Improving Quality, and Promoting Usability. SAGE Publication. Thousand Oak, CA 2021. p.515