Process tracing

Process tracing is a case-based approach to causal inference which focuses on the use of clues within a case (causal-process observations, CPOs) to adjudicate between alternative possible explanations. 

Process tracing involves four types of causal tests -

  • 'straw in the wind', which lends support for an explanation without definitively ruling it in or out,
  • 'hoop', failed when examination of a case shows the presence of a necessary causal condition,when the outcome of interest is not present. Common hoop conditions are more persuasive than uncommon ones
  • 'smoking gun', passed when examination of a case shows the presence of a sufficient causal condition. Uncommon smoking gun conditions are more persuasive than common ones
  • 'doubly definitive' passed when examination of a case shows that a condition is both necessary and sufficient support for the explanation. These tend to be rare.

Process tracing can be used both to see if results are consistent with the program theory (theory of change) and to see if alternative explanations can be ruled out.


This IIED Brief, Clearing the fog: new tools for improving the credibility of impact claims discusses the use of process tracing in some of IIED's research in Uganda


Expand to view all resources related to 'Process tracing'

This page is a Stub (a minimal version of a page). You can help expand it. Contact Us to recommend resources or volunteer to expand the description.

'Process tracing' is referenced in: