- Logic models are graphical representations of the theory underlying a
They assist the evaluator in identifying program objectives and activities, and
linkages between them.
- Logic models can be used for both primary and secondary prevention
programs. They can be helpful not only in the beginning phases of an evaluation,
but also in the initial and ongoing changes of the program.
- To develop a logic model, the evaluator must identify desired program
outcomes, specify program activities, and specify characteristics of the target
This section describes logic models, what they are, and how to build them. A
logic model is a graphic representation of the theory that underlies a program's
goals. Logic models are used in identifying program objectives, activities, and
expected outcomes, and in finding the linkages between them. They can be used in
both program development and the early phase of program evaluation.
|Throughout this section, the evaluator should refer to three figures.
2.1 is an example of a logic model that was developed for an existing prevention
program being used by USAF-FAP: the New Parent Support Program (NPSP). The
graphic model was developed primarily on the basis of program documentation, and
then elaborated on by program staff. Logic models are most useful for complex,
multi-step programs with outcomes that are measured at several different points.
However, logic models can also be used in primary prevention programs. In Figure
2.2, a preliminary and hypothetical logic model that could be applied to a
primary prevention program is provided, such as a class for parents of young
children. While it is not as complex as Figure
2.1, Figure 2.2 demonstrates that
logic models are useful even with less complex programs. Indeed, they are often
quite useful in planning stages when efforts are being made to operationalize
program goals and activities. Figure 2.3 is a blank model that can be
photocopied and used to describe the program under evaluation.
For each of the major components, sample worksheets are provided that are
designed to help the evaluator identify program specifics. There are copies of
these in the appendix of this section that can be photocopied and used while
developing a model. The worksheets provide more detail than will actually be
needed for a graphic model. But this level of detail will help the evaluator
conceptualize the program more fully. Once this information has been summarized
on the worksheets, the evaluator can transfer it to the blank logic model in