Irregularity on a Binet Examination as a Measure of Its Reliability

The writer became much interested, while serving as Assistant Psychologist at the Boston Psychopathic Hospital in the summer of 1916, in "irregularity" on a psychological examination as shown by insane patients. The results of a special study of this subject, using the Point Scale, have already appeared,1 and were summarized briefly in a paper at the annual meetings of the Psychological Association in December, 1917. In this paper a method for stating "irregularity" on the Binet scale was also suggested. Briefly, this method consisted in adding together the number of months failed below the mental age (each failure being multiplied by the number of years away from the mental age at which the failure occurred) and the number of months passed above the mental age (each success, again, being multiplied by its distance, on the scale, from the mental age). The present paper is a brief report of results obtained, using this method of figuring the "scatter," with the Stanford Binet scale. A word should first be said in explanation of the method. The method for stating "scatter" most in the spirit of the Binet scale would, the writer believes, be simply to add together the failures