The focus on results in development agencies has led to increased focus on impact evaluation to demonstrate the effectiveness of development programmes. A range of methods are available for counterfactual analysis of infrastructure interventions, as illustrated by the variety of papers in this...

A good-quality impact evaluation is based on an analysis of the theory of change for the intervention. Analysis of different parts of this causal chain, and the underlying assumptions, necessarily requires use of a variety of research methods. The method should fit the question, not the other...

Randomised control trials (RCTs) analyse what difference a programme makes through comparing those in the programme to a control group who do not receive it. Random assignment to the project and control groups overcomes selection bias which will otherwise occur from programme placement or...

We provide a ‘how to’ guide to undertake systematic reviews of effects in international development, by which we mean, synthesis of literature relating to the effectiveness of particular development interventions. Our remit includes determining the review's questions and scope, literature...

Systematic reviews are currently in high demand in international development. At least 100 new reviews are ongoing or already completed on a range of topics across the board in international development, many of which were commissioned by policy-making agencies. These new reviews need to be...

The International Initiative for Impact Evaluation (3ie) is a new organisation devoted to enhancing development effectiveness through supporting the production and use of evidence from rigorous impact studies. This paper outlines the theory of change that underlies 3ie's mission and the...

Calls for rigorous impact evaluation have been accompanied by the quest not just to find out what works but why. It is widely accepted that a theory-based approach to impact evaluation, one that maps out the causal chain from inputs to outcomes and impact and tests the underlying assumptions,...