Logic models are tools used by program managers and evaluators to describe the effectiveness of their programs. The model, usually a narrative or graphical depiction of the process, describes logical linkages among program resources, activities, outputs, audiences, and short-, intermediate-, and long-term outcomes related to a specific problem or situation. Once a program has been described in terms of the logic model, critical measures of performance can be identified. (Paul McCawley's The Logic Model for Program Planning and Evaluation is an excellent introduction to this topic).
Developing a Logic Model
In general, logic models take into account:
Inputs: financial, staff, equipment and other resources invested to support the program.
Activities: structured services intended to deliver what is necessary to achieve objectives.
Outputs: observable and measurable events resulting from program implementation.
Short-term outcomes: immediate changes realized especially during program participation.
Long-term outcomes: changes realized after program participation.
External factors: conditions outside the program that affect implementation and outcomes.
Developing a logic model requires a program planner to think systematically about what they want their program to accomplish and how it will be done. The logic model should illustrate the linkages of among the elements of the program including the goal, objectives, resources, activities, process measures, outcomes, outcome measures, and external factors. Using the logic model as a planning tool is especially valuable when we focus on what it is that we want to communicate to others. The process generally involves discussions with service providers and funders the goals of and rationales behind program organization and content, the examiniation of planning documents and program reports, and a review of research findings on similar programs or problems. A literature review may be particularly helpful in identifying plausible causal links and any factors other than the program which should be considered in the evaluation.
Other Sample Logic Models
Below are some excellent resources for understanding and developing logic models: