What is impact?

Resource link

This discussion paper discusses the meaning of 'impact', moving beyond methodological debates to present different perspectives and dimensions that can affect how impact could be framed and evaluated.

This resource and the following information was contributed to BetterEvaluation by Hannah Caddick (ODI).

Authors and their affiliation

Simon Hearn (ODI) and Anne L. Buffardi (ODI)

Key features

This discussion paper does not propose a single definition of impact or debate existing definitions but instead encourages development programmes to structure an explicit conversation about how different stakeholders conceive of and are using the term impact in order to come to a shared understanding.

The paper’s introduction explains why different definitions of ‘impact’ may be problematic, and why clarifying what it means in a particular context is important. Table one provides an overview of different definitions of impact used by 11 international development organisations – from the World Bank to the Global Environment Facility. Chapter 3 presents some of the contrasting and overlapping definitions of impact used by different organisations to stress the diversity and flexibility of the term. Chapter 4 identifies six aspects of impact and suggests questions to ask of the project, context or stakeholders to help establish a shared understanding of the term.  

How have you used or intend on using this resource?

This paper provides a helpful reminder that shared understanding is essential in the delivery and in the monitoring, evaluation and learning of development programmes. It gives useful suggestions for how to approach the question of ‘impact’ and make sure different stakeholders are all talking about the same thing. 

Why would you recommend it to other people?

The paper walks through some of the most common definitions and uses of impact in international development and guides the reader through a set of questions to help them clearly communicate what they mean by impact.


Hearn, S. and Buffardi, A.L. (2016) ‘What is impact?’. A Methods Lab publication. London: Overseas Development Institute. Retrieved from: https://odi.org/en/publications/what-is-impact/

'What is impact?' is referenced in: