Contribution Analysis: An Approach to Exploring Cause and Effect
Questions of cause and effect are critical to assessing the performance of programmes and projects. When it is not practical to design an experiment to assess performance, contribution analysis can provide credible assessments of cause and effect. Verifying the theory of change that the programme is based on, and paying attention to other factors that may influence the outcomes, provides reasonable evidence about the contribution being made by the programme.
Contribution analysis explores attribution through assessing the contribution a programme is making to observed results. It sets out to verify the theory of change behind a programme and, at the same time, takes into consideration other influencing factors. Causality is inferred from the following evidence:
- The programme is based on a reasoned theory of change: the assumptions behind why the program is expected to work are sound, are plausible, and are agreed upon by at least some of the key players.
- The activities of the programme were implemented.
- The theory of change is verified by evidence: the chain of expected results occurred.
- Other factors influencing the programme were assessed and were either shown not to have made a significant contribution or, if they did, the relative contribution was recognised.
Contribution analysis is useful in situations where the programme is not experimental—there is little or no scope for varying how the program is implemented—and the programme has been funded on the basis of a theory of change. Many managers and evaluators assessing the performance of programmes face this situation. Kotvojs (2006) describes one way of using contribution analysis in a development context, "as a means to consider progress towards outputs and intermediate and end outcomes" (p. 1).