ABSTRACT
Historically, group designs were not the favoredmethodology of psychologists and psychiatrists. In actuality, many of the early developments in experimental psychology are based on designs reflecting ideographic perspectives-those focused on the study of individuals and exemplified by case studies and singlecase experimental designs. For instance, Pavlov, Wundt, and Piaget all derived basic propositions regarding human capacities and behavior through various forms of single case investigation (Kratochwill &Mace, 1984). However, since the 1950s, the field of experimental psychology has steadily moved toward a preference for a nomothetic view in research design-a perspective concerned with uncoveringmore general statements and laws about behavior. At the heart of the nomothetic perspective is the desire to examine persons in groups, so that the researcher may comprehend how people on average will react to a particular set of experimental conditions (Hampton, 1998).
