Analyzing grids: New and traditional approaches
While everyone knows the Repertory Grid made its debut in the first volume of Kelly's 1955 two-volume The Psychology of Personal Constructs (Kelly, 1955/1991), it is probably not so well known that Kelly also presented a method of a naly sis of grid data in that volume. He referred to it as a form of C(factor analysis," and termed it a (Cnonparametric solution to the problem" which "gives essentially the same answer that conventional factorial methods give and in such a small fraction of the time that the method is quite feasible for clinical use." This method was subsequently programmed for a computer as early as 1962 but a published version did not emerge until 1986 in the UK (Potter and Coshall, 1986). However, the earliest application of factor analysis was that of Levy and Dugan (1956). They also introduced the notion of using ratings to locate elements on constructs (and thus simplity the calculation of correlations for factor analysis) and showed rotated factor loadings for constructs. At the same time a tradition of using indices to summarize grids was started with Bieri's cognitive complexity-simplicity index (Bieri, 1955). The summary index tradition has continued in North America to this day, while the representation tradition has developed in the UK and Europe. In this chapter, we review traditional summary indices and describe recent developments in measuring the concepts of conflict and cognitive complexity. We also review ways traditional and new approaches to representing grid data.