Notions of Validity in Qualitative Research Methodology

This essay has two objectives. The first is to argue, from both philosophical and empirical perspectives, that all approaches to inquiry are inherently qualitative in nature. The second is to demonstrate that the evolution of inquiry systems has progressed through five distinct stages, each of which can be distinguished by a particular set of assumptions and procedures that inform the inquiry process. Each evolutionary stage also possesses its own characteristic guarantor of validity, that is, a key rule or set of rules meant to insure that the given approach to inquiry indeed measures that which it purports to measure. Implications for knowledge creation and utilization are discussed in some detail.