How to Create a Model of Change?

A model of change clarifies underlying assumptions about how the proposed intervention will lead to the expected outcomes and goals of the intervention. While this concept sounds like a simple one, it is often the weakest element of an evaluation plan. Development of a clear and correct model of change is the most critical step in the development of a sound evaluation plan.

What is a model of change? A model of change refers to the specific set of relationships that one believes connects the intervention to the achievement of the impact objectives of the project. The model should specify how the proposed interventions will lead to these goals.

A simple model of change for this project might begin with the assumption that multimedia methods are more effective for presenting knowledge than didactic lectures. Because multimedia methods are more effective, students will learn more, retain more, and, therefore, will have a higher probability of passing the course.

If this model reflects the assumptions underlying the proposed intervention and how it leads to achievement of the project goals, investigators should try to assess each of the proposed links in the model of change. For example, do the students who use the multimedia system learn more than those taught by the traditional lecture system? Does use of multimedia result in a higher percentage of students passing the course? Does it result in students liking chemistry more?

It could be that the intervention does increase learning (let’s say that the students develop better conceptual knowledge of chemistry due to use of interactive simulations, as reflected in their laboratory worksheets) but this knowledge may not lead to a higher percentage of students passing the course.

This “failure to pass” could occur because the course grade is based on a curve or because the exams do not tap this increased conceptual understanding. Alternatively, students could learn more, perform better in the course, but still choose to drop out of chemistry because – even when passing the course – they do not like chemistry more. Or it could be that they like chemistry so much after participating in the multimedia intervention that they decide to take more “chemistry.

The important point here is that the set of relationships theorized to exist between the intervention and the goals of the project must be clearly defined. To the extent possible, each of the defined relationships should then be measured as part of the evaluation plan, allowing you to determine why and how the project either succeeded in reaching its goals or failed to do so. The more specific you are in developing your model of change, the more useful the information generated by the evaluation will be.

Of course, few projects have sufficient resources to assess all assumptions. They must choose which of the relationships that exist in their model to test. These choices should be based on:

1) What can be measured well, given available resources?

2) Where problems can be anticipated

3) Where investigators have control and can improve the intervention or project based on the results

Action Steps for Investigators:

1. Develop a model of change for the project, making it as specific and complete as possible.

2. Review each of the assumptions (lines) in the model. Using the criteria presented above, identify the priority assumptions to be addressed through the project evaluation.