John Mayne

John Mayne (1943–2020) was a Canadian program-evaluation researcher and public-sector adviser best known for developing contribution analysis. He worked in the Canadian public service, including the Office of the Auditor General of Canada, and later advised organizations on evaluation and performance management.

Mayne developed contribution analysis to address a difficult question: when several forces could have produced an observed result, what evidence supports a claim that a particular program helped bring it about? His approach begins with a theory of change—an account of how activities are expected to lead through a sequence of results. Evaluators then examine whether the activities took place, whether the expected changes appeared, whether the links between them are credible, and what other factors might explain the results.

In his 2008 account, Mayne distinguished a limited assessment based on delivered outputs and an established theory of change from a stronger assessment that also finds evidence of results within a program’s direct influence. The distinction matters because completing planned work does not, by itself, show that the intended change occurred. Contribution analysis builds and challenges an evidence-based explanation of a program’s role; it is not a claim that the program acted alone or a numerical estimate of its isolated effect. Mayne continued to develop the approach in later work on causal claims and theories of change.