The purpose of this study was to see the relation of the detectability measure of the signal detection model and other educational test scores such as the personality test, the course of study, and I. Q. test. The experiments were designed to determine how well Japanese students in high school can evaluate the intelligibility of their own English hearing reception, applying the detectability measure of the signal detection model. Two types of English hearing tests were given to the Ss English perception and meaning. The general testing procedure employed was identical to the standard English intelligibility test procedure with one addition: After the listener responded to each test item, he reported his judged accuracy of his own reception. The rating scale with five categories was as follows. 5. I am certain I understood the message correctly. 4. I am fairly certain I undetstood the message correctly. 3. Undecided. 2. I am fairly sure I did not understand the message correctly. 1. I am certain I did not understand the message correctly. The data were analysed in terms of ROC curve and the detectability scores (dr) were obtained. To obtain personality test scores, Yatabe-Guilford Personality Test, General Anxiety Test, Myers Briggs Type Indicator, and TPI were given to the senior high 1st-year students. Yatabe-Guilford Test, General Anxiaety Test, and Nagashima Adjustment Inventory were given to the junior high school 1st-year students. Correlation coefficients between the detectability measure and the personality test scores were obtained. The results indicated that depressive, neurotic, introversive scores of personality tests had negative correlations with the detectability measure. On the contrary, extraversive, active scores of personality tests had positive correlations with the detectability scores. The correlation coefficients between the detectability measure and the achivement scores of the courses of study did not show the clear results among different school years. In general, in higher levels of high school there was a closer relation between them. The correlation coefficients between the detectability score and Tanaka-Binet test score were positive in senior high school 1st-year, but there was no correlation in junior high school 1st-year. Possible applications to educational problems of these studies and the detectability measure were discussed.