CHAPTER Six Enduring Controversies in Measurement and Statistics INTRODUCTION 9 "There is, of course, nothing strange or scandalous about divisions of opinion among scientists. This is a condition for scientific progress" (Grove, 1989, p. 133). "Criticism is the mother of methodology" (Abelson's 8th law, 1995, p. xv). Controversy is one of the engines of scientific progress. Proponents of one point of view debate those who hold a different point of view, ideally using empirical (data-based) and rational (logic- based) arguments. When there is no clear winner, these debates can carry on over decades, or even centuries. The fields of measurement and statistics are no strangers to such debates (Abelson, 1995; Cowles, 1989; Stigler, 1986, 1999).