With millions of tests being administered each year, you would think that the "Cumulative Quantitative Measurement Model" would be well known. Yet it’s been relegated to an occasional footnote, if that, in many texts on testing.

In brief, when identifying psychopathology, problematic behaviors and DSM-IV disorders or when predicting their occurrence and/or recidivism, their symptoms, characteristics and traits are measured "additively." For example, with regard to alcohol use, the more self-admissions to alcohol use or abuse, the more severe the client’s alcohol abuse and the higher the probability of future abuse. Similar logic applies to other attitudes and behaviors that are measured. With regard to mental disorders, the more self-admissions to symptoms (DSM-IV) of a disorder, the higher the probability of that client having that mental disorder. Similarly, the more admissions to predictive factors like criminogenic needs contribute to a higher-probability of recidivism.

This model is so fundamental that most evaluators, assessors and screeners take it for granted. Yet, like any theory it serves a purpose. Jane Loevinger (Objective tests as instruments of psychological theory, Psychological Reports, 3,635-694, 1957) and Walter Mischell (Personality and Assessment, Wiley, New York, 1968) discuss the Cumulative Quantitative Measurement Model.

This anecdote is included in the www.riskandneeds.com site because we wanted to share it with site visitors. It reminds us of all the things in the testing field that we assume or take for granted.