ABSTRACT
One of the main objectives of this book is to help you learn to evaluate the merit of a research study. Validity is the term most often used to judge the quality or merit of a particular study. We use the term research validity when discussing the merit of a whole study to distinguish the term from validity of the measurement of a variable. It is necessary to learn about research validity for two reasons. The first is that it helps develop criteria by which to design and judge one’s own research. Second, and perhaps more important, it makes you a better consumer of research. Persons embarking on careers in applied areas need to be able to judge the merit of research. For example, if one is to pick and choose among alternative treatment or intervention modalities, one needs to be able to evaluate the research literature.
