THE FIRST EDITION OF THIS BOOK APPEARED IN 1980. AT THE TIME, THERE WAS VERY LITTLE LITERATURE DEDICATED TO THE NUTS AND BOLTS OF HOW TO DO QUALITATIVE INQUIRY, ESPECIALLY AS AN APPROACH TO PROGRAM EVALUATION. THE SECOND EDITION, IN 1990, BEGAN THE PROCESS, CONTINUED IN THIS LATEST REVISION, OF INTEGRATING THEORY AND PRACTICE. THE THIRD EDITION, PUBLISHED IN 2002, NOTED THE GROWTH OF INTEREST IN QUALITATIVE METHODS AND OBSERVED THAT “THE UPSHOT OF ALL THE DEVELOPMENTAL WORK IN QUALITATIVE METHODS IS THAT THERE IS NOW AS MUCH VARIATION AMONG QUALITATIVE RESEARCHERS AS THERE IS BETWEEN QUALITATIVELY AND QUANTITATIVELY ORIENTED SCHOLARS AND EVALUATORS” (PATTON, 2002, P. XXII). THUS, THE PRIMARY PURPOSE OF THE THIRD EDITION WAS TO SORT OUT THE MAJOR ALTERNATIVE PERSPECTIVES IN THE DIVERSITY OF QUALITATIVE APPROACHES THAT HAD EMERGED AND EXAMINE THE INFLUENCES OF THAT DIVERSITY ON APPLICATIONS, ESPECIALLY BUT NOT EXCLUSIVELY IN PROGRAM EVALUATION, POLICY ANALYSIS, AND ACTION RESEARCH, AND ACROSS APPLIED SOCIAL SCIENCES GENERALLY—WHICH BRINGS US TO THIS FOURTH EDITION.