It is a little over ten years since Chidamber and Kemerer's obje ct-oriented (OO) metric suite which included the Lack of Cohesion Of Methods (LCOM) metric was rst proposed 9]. Despite considerable e ort both theoretically and empirically sincethen, the softwar eengineering community is still no nearer nding a generally ac cepted de nition or measure of OO cohesion. Y et,achieving highly cohesive software is a cornerstone of software comprehension and hence, maintainability. In this paper, we suggest a number of suppositions as to why a de nition has eluded (and we feel will continue to elude) us. We supp ortthese suppositions with empirical evidence from three large C++ systems and a cohesion metric based on the parameters of the class methods we also draw from other related work. Two major conclusions emerge from the study. Firstly, any sensible cohesion metric does at least provide insight into the featur esof the systems being analysed. Secondly however, and less reassuringly...