One of the main tasks of scientific activity is the construction of expla nations and, indeed, explanations abound in the sociological literature. Many sociological analyses are wholly devoted to the task of explaining some social phenomenon, while virtually every report of empirical research contains a section variously called 'interpretation', 'discussion' or 'conclusions', in which the investigator offers an explanation for his results. Sometimes these explanations occur in the introduction to a research report as a rationale for some particular hypothesis or as a justification for doing the reported study. Although these explanations are informal and discursive in nature, it is very clear that their objectives are similar to the objectives of highly formalized and rigorous explan atory systems. It is, perhaps, paradoxical that despite the abundance of explanatory efforts in sociology and despite the similarity in the goals of explanation between sociology and other sciences, there are very few satisfactory sociological explanations. Our explanations are unsatisfactory because they do not lead anywhere. They are not useful in the pursuit of further understanding of social phenomena. Most often sociological explana tions are ad hoc ideas applied to one particular situation and rarely, if ever, used again. Typically, these interpretations are plausible, cer tainly possible, and often interesting, but the striking thing is that the ideas which one author uses to explain his observations are rarely en countered again, either in the same author's later work or in the works of other sociologists. Furthermore, these explanations seldom generate new research, for they are often untestable; or, if they are testable, they are presented without any guidelines that would allow another investi gator to apply them to some other situation, study, or phenomenon. If it is true that sociological explanations are inherently ad hoc, it becomes important to examine what makes them ad hoc, for through understanding those features of our formulations that limit their use fulness, we can arrive at guidelines for more fruitful explanations. It is