Questions and Basic Premises of the Project

From its very first collection of five articles (Wallerstein , 1956), PRP has been involved in presenting its methods and design to the professional world on the basis, which we felt important, that the field of systematic clinical psychotherapy research was still in that early developmental state where issues of methods advancement properly preceded attention to substance advancement.1 Subsequently, as the project moved through its data-collecting phase in accord with the methods and the design that had been constructed, presentation was made (in the third collection, of three articles, in 1960) of what we called the “operational problems of psychotherapy research”: the problems encountered, and the choices available to cope with them, in implementing such a naturalistic study of change brought about by psychotherapy (Hall & Wallerstein, 1960; Wallerstein & Robbins, 1960). The entire overall structure of methods, of design, of operational problems, and (sketchily) of paths of data analysis and the directions in which preliminary findings pointed has been presented in highly schematized and condensed form at a number of points in progress—updated each time (see Robbins & Wallerstein, 1959; Wallerstein, 1961, 1966 [midway point], and 1968 [semifinal point]). In 1977, this was all brought together into a total overview (again, necessarily abbreviated) (Wallerstein, 1977b). In Section II of this book, I trace the evolution of the PRP methods, design, operational problems, pathways to data analysis and write-up, and handling of the issue of controls, in the kind of full detail not possible to this point within the constraints of journal presentation. This detailed presentation of plan is a most necessary pan of the evidential base for the subsequent assessment by the reader of both the “intrinsic validity” (see p. 12) of our findings and conclusions, as well as of the degree to which we have been able to subject the subtle and complex phenomena of subjective menta