A Randomized Evaluation is a type of Impact Evaluation that uses random assignment to allocate resources, run programs, or apply policies as part of the study design. Like all impact evaluations, the main purpose of randomized evaluations is to determine whether a program has an impact, and more specifically, to quantify how large that impact is. Impact evaluations measure program effectiveness typically by comparing outcomes of those (individuals, communities, schools, etc) who received the program against those who did not. There are many methods of doing this. But randomized evaluations are generally considered the most rigorous and, all else equal, produce the most accurate (i.e. unbiased) results.            

The methodology section covers the what, why, who, when, and how of randomized evaluations.

For more resources on randomized evaluations, see:

• Evaluating Social Programs: Executive Education at J-PAL

• A free online version of the course

• Using Randomization in Development Economics Research: A Toolkit
  E. Duflo, M. Kremer and R. Glennerster

• Randomized Evaluations of Educational Programs in Developing Countries: Some Lessons                                                                                       
  M. Kremer

• Field Experiments in Development Economics                                                                                      
  E. Duflo, January 2006

• Use of Randomization in the Evaluation of Development Effectiveness                                      
  E. Duflo and M. Kremer, July 2003

• Scaling Up and Evaluation         
  E. Duflo, May 2003

• Nonexperimental Versus Experimental Estimates of Earnings Impacts   S. Glazerman, D. Levy and D. Myers, May 2003