The Mystery of Missing Psychometric <i>Corpus</i> : The Case of the Technological Cart Before the Scientific Horse

Psychometrics, the science sustaining psychological test construction and use, has consistently ignored logical criticism of its foundations, even though science as a cognitive enterprise requires criticism. This accumulating corpus of criticisms is generally unacknowledged in histories of the discipline, in textbooks, and in course curricula. Thus, there is a mystery here as to why this critical resource is missing. Considering three critical offerings from before 1950, it is clear that by mid-century, psychometric methods, consistently marketed as instruments of scientific measurement, were bereft of evidence supporting that boast. A solution to this mystery is proposed.