Logic Models and Theory-Based Evaluation Approaches
Logic Models
One of the criticisms of objectives-oriented evaluation is that it tells us little about how the program achieves its objectives. This can be a particular problem when programs fail to achieve their objectives, because the evaluation can provide little advice on how to do so. Logic models have developed as an extension of objectives-oriented evaluation and are designed to fill in those steps between the program and its objectives. Typically, logic models require program planners or evaluators to identify program inputs, activities, outputs, and outcomes, with outcomes reflecting longer-term objectives or goals of the program and outputs
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representing immediate program impacts. The model, typically presented in a diagram form, illustrates the logic of the program.
A typical logic model may include the following:
Inputs—annual budgets, staffing facilities, equipment, and materials needed to run the program
Activities—weekly sessions, curriculum, workshops, conferences, recruit- ment, clinical services, newsletters, staff training, all the key components of the program
Outputs—numbers of participants or clients served each week, number of class meetings, hours of direct service to each participant, number of newsletters and other immediate program products
Immediate, intermediate, long-term, and ultimate outcomes—the longitudi- nal goals for participant change (development)
Logic models are widely used in program planning and evaluation today. They have influenced evaluation by filling in the “black box” between the program and its objectives. Evaluators can use logic models to help program staff articulate and discuss their assumptions about how their program might achieve its goals and what elements are important to evaluate at any given time and generally to build internal evaluation capacity or the ability to think in an evaluative way. (See Taylor-Powell & Boyd [2008] for an example of the use of logic models in cooper- ative extension to build organizational capacity. Knowlton and Phillips [2009] also provide guidance for building logic models.) The United Way of America was one of the major organizations to bring logic models to evaluation through the logic- model-based approach it requires for the organizations it funds (United Way, 1996). Other foundations, such as the W.K. Kellogg Foundation and the Annie E. Casey Foundation, have also been instrumental in training organizations in the use of logic models to improve program planning and evaluation.