Quasi-experimental design and methods

This guide, written by Howard White and Shagun Sabarwal for UNICEF looks at the use of quasi-experimental design and methods in impact evaluation.

The paper provides a brief overview and then provides an outline of when it is appropriate to use and some of the ethical and practical limitations of its use.

Excerpt

"Quasi-experimental research designs, like experimental designs, test causal hypotheses. In both experimental (i.e., randomized controlled trials or RCTs) and quasi-experimental designs, the programme or policy is viewed as an ‘intervention’ in which a treatment – comprising the elements of the programme/policy being evaluated – is tested for how well it achieves its objectives, as measured by a pre specified set of indicators (see Brief No. 7, Randomized Controlled Trials). A quasi-experimental design by definition lacks random assignment, however. Assignment to conditions (treatment versus no treatment or comparison) is by means of self-selection (by which participants choose treatment for themselves) or administrator selection (e.g., by officials, teachers, policymakers and so on) or both of these routes."

Contents

• Quasi-experimental design and methods: a brief description
• When is it appropriate to use quasi- experimental methods?
• Quasi-experimental methods for constructing comparison groups
• Quasi-experimental methods for data analysis
• Ethical issues and practical limitations
• Which other methods work well with this one?
• Presentation of results and analysis
• Example of good practices
• Examples of challenges