Primary Source: Patton, C. V, and Sawicki, D. S. (1993) Basic Methods of Policy Analysis, Second Edition. Prentice Hall: Englwood Cliffs, NJ.

 

In an attempt to identify what changes might have been brought about by a program, the before-and-after comparison approach has been modified to include a comparison of relevant criteria in the locale with the program to a locale without the program, both before and after implementation. The obvious limitations here are the selection of appropriate comparison locales or groups and the assumption that changes observed in the target locale can be attributed to the policy or program. While the use of a comparison community shows awareness of the need for a control group, the expense of such comparison groups, without other aspects of the experimental design approach.