Over the last 20 years, theory-based approaches—under various names ― have increasingly moved into the mainstream of thinking and practice about how interventions (i.e., programs, policies, initiatives or projects) are designed, described, measured and evaluated. During that time, theory-based approaches have demonstrated promise in helping evaluators address a variety of challenges, such as coming to terms with the inherent complexity of certain types of interventions and overcoming the limitations of experimental evaluation designs.

To help ensure that evaluation continues to play a key role in providing a neutral, evidence-based assessment of the value for money (i.e., relevance and performance) of federal government programs, the Treasury Board of Canada Secretariat recognizes the importance of expanding the “tool box” available to federal evaluators. Theory-based approaches to evaluation represent a potentially powerful tool.