Types of Logic Models

Logic models should assist projects in describing, planning, implementing, monitoring, and/or appraising a project in the most practical manner. There is no magic formula when it comes to identifying and constructing a logic model. Each project and its staff will address logic model development with different aims and approaches. The flexibility of the logic modeling process allows for a variety of perspectives and approaches to be described within the context of a project's scope of work. Following are examples of some different types of logic models that may be useful to NIDILRR grantees. These are not intended to suggest a comprehensive description of all available types of logic models.

Theory Approach Logic Model

A logic model can be constructed to reflect a project's theory of how it is going to produce change within a specific target system. This is sometimes called a Theory Approach Logic Model (W. K. Kellogg Foundation, 2001). This model is based upon the theoretical premises upon which a project was designed and provides a theory-based rationale for the exploration, problems, issues, needs to be pursued by the project, and how the project intends to produce "solutions" connecting project results with proven strategies. The rationale should explain why a project design is likely to be successful.

Theory Approach Logic Models are often found in grant proposals because they make a case for how the elements of the project design fit together to produce desired outcomes. These logic models emphasize the problem or concern addressed by the project design and the theory-based principles upon which activities are developed and results are expected. Emphasis in a Theory Approach Logic Model is often placed on the following elements:

  • the problem(s), concern(s), issue(s) the project is targeting for solution;
  • the unique assets the project or organization brings to the project design to address the problem;
  • the assumptions made from theory underpinning the project strategies;
  • the environmental, social, or contextual conditions that will influence the outcomes expected through project activities;
  • the project activities that are based on identified, proven interventions addressing similar problems or issues; and
  • the outcomes, results, or changes expected due to the project's activities.

Outcomes Approach Logic Model

This model emphasizes the rationale between the project's activities and the expected or targeted outcomes. An outcomes-oriented logic model describes the linkage between planned activities and their expected outcomes. An activity or set of related activities is projected to cause an outcome or set of outcomes to occur in this type of modeling.

The Outcomes Approach Logic Model is highly descriptive of specific activities and expected outcomes and would tend to emphasize the following elements:

  • the outputs, deliverables, products, or events your project will produce;
  • the short and mid-term outcomes expected over time that the project actions will produce;
  • the long-term benefits or impact that your project work is expected to produce;
  • the specific activities that will produce specific outcomes or impacts; and
  • the factors that may positively or negatively influence the outcomes predicted (W. K. Kellogg Foundation, 2001).

Activities Approach Logic Model

This model emphasizes how the project's activities stem from the available resources and are linked to the expected outcomes. Emphasis in this type of model is placed on the activities, which are usually described in fine detail. Activities describe the scope-of-work of the project and are often placed in time to indicate when certain activities will begin and end. This type of model can be used as a management tool to assess activity initiation, culmination, and demonstration of expected results.

        An Activities Approach Logic Model often emphasizes the following elements:

  • the situation or purpose of your project that focuses activities;
  • the target systems that will be influenced by your project activities;
  • the specific activities that will be implemented and the specific outputs and outcomes that will result from that work; and
  • the measurements and data sources that will be used to determine the project's effectiveness in reaching targeted outcomes (W. K. Kellogg Foundation, 2001).

Research Performance Logic Models

Logic models are not always linear in construction, with one element leading directly to the next. They are flexible enough not to require such a relationship among their elements. For example, research-oriented projects often are best described in a recurring "loop" between the project's input and activities, its research design and implementation, and its results or output. Related research is often required to produce sufficient confidence or rigor to be used by others key audiences or systems to produce change or other effects. This suggests that the output of one research activity constitutes the input for another research activity and so on – until reliable results are produced. In a logic model, this could look like:

Input → Research Activities → Output → Outcomes, (back to Inputs to repeat)

Generally speaking, no single research activity and accompanying result is sufficient to expect widespread implementation and short- and mid-term outcomes, and long-range impact. Rather, research is characterized as an iterative process where the results of research are subject to review, analysis, and replication before they may be fully accepted by the scientific community as sufficient to base decisions upon in the real world. To be most useful, logic models need to reflect this reality in the production of research-based findings that can be widely used.


W. K. Kellogg Foundation. (2004). Logic model development guide. Battle Creek, MI: Author. Available from https://www.wkkf.org/resource-directory/resources/2004/01/logic-model-development-guide. (Download is free but must enter an email address.)

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