Functions of logic models

Logic models support the specification of ideas and their internal and external communication; implicit assumptions of cause-effect relationships should be made explicit, and a common understanding should be reached about which measures can be implemented with what short, medium and long-term goals.

Besides this general function of goal clarification, logic models can be developed with specific functions or key aspects:

1. Theory of change models: a clear statement of how and why a project or program will succeed is especially important when funding requests are submitted. Logic models like these emphasise underlying assumptions about  thedemand or the problem situation and the reasoning behind the measures.
2. Activity models: an accurate presentation the steps helps the planning and management of a project or program. These models focus on the implementation process.
3. Outcome models: linking the activities to the expected results and precisely specifying the short, medium and long-term goals make evaluating of a project or program easier. These models put emphasis on the link between measures and results.

Examples
In the following link a brief fictional project is described with example models shown afterwards: Logical models - Examples

Background information

• For any given project or program there is never just ONE "correct" model! A specific logic model always provides just one of many possible perspectives; it is never possible to take into account all the influencing factors.
• Logic models change over time! The progress of a project or program is often also determined by environmental conditions which cannot be foreseen or controlled. Thus, as you adapt your project or program to general conditions, the model changes as well.
• On the website of W.K. Kellogg Foundation you can find a detailed guide about how to develop logic models: http://www.wkkf.org/default.aspx?tabid=134&CID=-1&CatID=284&NID=212&LanguageID=0&Letter=W (there: W.K. Kellogg Foundation Logic Model Development Guide, pdf, 1.3 MB; external)