Prepared by Elliot Stern for the Big Lottery Fund, Bond, Comic Relief
and the Department for International Development, May 2015
Available as pdf
1. Introduction and scope 2
2. What is impact evaluation? 4
Defining impact and impact evaluation 4
Linking cause and effect 5
Explanation and the role of ‘theory’ 7
Who defines impact? 7
Impact evaluation and other evaluation approaches 8
Main messages 9
3. Frameworks for designing impact evaluation 10
Designs that support causal claims 10
The design triangle 11
Evaluation questions 11
Evaluation designs 13
Programme attributes 14
Main messages 15
4. What different designs and methods can do 16
Causal inference: linking cause and effect 16
Main types of impact evaluation design 20
The contemporary importance of the ‘contributory’ cause 21
Revisiting the ‘design triangle’ 21
Main messages 23
5. Using this guide 24
Drawing up terms of reference and assessing proposals for impact evaluations 25
Assessing proposals 25
Quality of reports and findings 27
Strengths of conclusions and recommendations 28
Using findings from impact evaluations 29
Main messages 29
Annex 30
