Theory-Based Evaluation: Reflections Ten Years On

Theory-based evaluation has developed significantly since Carol Weiss’s chapter was published ten years ago. In 1997 Weiss pointed to theory-based evaluation being mostly used in the areas of health promotion and risk prevention. The use of program theory is now commonplace and Weiss’s chapter has been cited in a wide range of program areas, including evaluations of energy conservation (New York State Energy Research and Development Authority, 2006), comprehensive community-based initiatives (Judge and Bauld, 2001), supported housing (Rog and Randolph, 2002), gaming and simulation (Kriz and Hense, 2006), and anticorruption activities (Marra, 2000). Along with this proliferation of activity has come a proliferation of terminology. Weiss referred to the use of the different terms program theory and logic models to refer to essentially similar concepts. Now there is an ever-longer list of labels that have been used, not with consistently distinct definitions, including theory-based, theory-driven, theory-oriented, theoryanchored, theory-of-change, intervention theory, outcomes hierarchies, program theory, and program logic. Despite the use of the term program, the method has been used for planning and evaluating interventions ranging from small projects to multisite projects, multiyear strategies and even whole-of-government processes (for example, Public Service Commission, South Africa, 2003). One of the biggest changes in the use of program theory since 1997 has been its increasing incorporation in program management processes. This phenomenon had occurred earlier in some places and program areas—for