Experiments and the experimental method form an important part of the repertoire of research methods that can be used in behavioral science research. However, problems ensue mainly because of the complex nature of the human subject vis-à-vis that of nonliving matter on which experiments are conducted in the natural sciences. It is to take care of such problems that specific experimental designs have been formulated, the use of which helps to control unwanted variance due to intervening and extraneous factors. Though a wide variety of experimental designs are available, a thorough understanding of each of them is imperative. While the right choice by a discerning researcher helps to bridge the gap between conceptual validity and statistical validity, a faulty selection of experimental design will lead to the obtaining of data which may be low on both reliability and validity.