The efficiency of matched samples: an empirical investigation.

Abstract

The general principles of matching and the appropriate statistical tests are discussed. The relative efficiency of matched and simple random samples in a variety of experimental situations is empirically assessed on a series of experiments simulated with the aid of an electronic computer. It is concluded that matching appears to be less efficient than covariance analysis on simple random samples for investigations involving quantitative response irrespective of whether the matching criteria are quantitative or qualitative. For investigations with all-or-none response, matching is a useful technique for ensuring group comparability and increasing the precision of the comparison. The effect of matching on the duration of experiments is also considered.