Abstract:
This paper discusses the 'commensurability conditions applying to the general linear model (GLM) and examines some of the more serious limitations entailed by the widespread and often uncritical use of the GLM, particularly in exploratory educational and psychosocial research. By an examination of the statistical properties of the GLM, it is argued that even in the context of explanatory research, where the conditions for statistical and substantive model 'commensurability' are most likely to hold, the GLM has notable weaknesses and limitations.