ARGUING CHALLENGES TO VALIDITY IN-FIELD RESEARCH - A REALIST PERSPECTIVE

Despite increasing popularity of the case study in government-commissi oned policy research and evaluation, doubts about the validity of fiel d research methods remain widespread in the academic literature. The n ew scientific realism challenges research based on conceptions of pred iction and control and supports the development of explanatory approac hes. In this article, a rationale for the central importance of field methods in education and social research is offered, a conception of t hreats to validity as rebuttals in a socially transacted argument abou t the plausibility of a knowledge claim is developed, and seven groups of threats to the validity of explanatory inferences are suggested.