Theory-based evaluation acknowledges that, intentionally or not, all programs depend on the beliefs influential stakeholders have about the causes and consequences of effective social action. These beliefs are what we call theories, and they guide us when we design, implement, and evaluate programs.
Theories live (imperfectly) in our minds. When we want to clarify them for ourselves or communicate them to others, we represent them as some combination of words and pictures. A popular representation is the ubiquitous logic model, which typically takes the form of box-and-arrow diagrams or relational matrices.
The common wisdom is that developing a logic model helps program staff and evaluators develop a better understanding of a program, which in turn leads to more effective action.
Not to put too fine a point on it, this last statement is a representation of a theory of logic models. I represented the theory with words, which have their limits, yet another form of representation might reveal, hide, or distort different aspects of the theory. In this case, my theory is simple and my representation is simple, so you quickly get the gist of my meaning. Simplicity has its virtues.
It also has its perils. A chief criticism of logic models is that they fail to promote effective action because they are vastly too simple to represent the complexity inherent in a program, its participants, or its social value. This criticism has become more vigorous over time and deserves attention. In considering it, however, I find myself drawn to the other side of the argument, not because I am especially wedded to logic models, but rather to defend the virtues of simplicity. Continue reading