The purpose of this investigation is to construct a new inventory for the measurement of neuroticism and extraversion-introversion. The First Trial InventoryAs the first trial, the author composed an inventory of 78 items, which was divided into 4 groups as follows; E-I Group (20 items), N Group (20 items), Eg-1Group (19 items), and Eg-2 Group (19 items). The inventory was administered to 156 junior high school pupils. The tetrachoric correlations between the items within each group were calculated, and factor analysis was executed by Thurstone's centroid method. The factors after orthogonal rotations of axes were interpreted as follows. Thinking introversion, and Social extraversion from the E-I group. Delicacy, Lack of Con fidence, and Anxiety from the N group. Self-sufficiency, and, Emotionality from the Eg-1 group. Ego-strenth, Ego-centricity, and Ego-defence from the Eg-2 group. The Second Trial InventoryAs the second step, another new inventory was composed discarding 8 items from the foregoing inventory, and adding 32 new items. The new inventory was divided into 5 groups as follows; E-I Group (20 items), D-C Group (22 items), Anx Group (20 items), S-Eg Group (20 items), As-Ce Group (20 items). The inventory was administered to 193 senior high school pupils. The factors extracted in this case were interpreted as follows; Social extraversion, and Thinking-introversion from the E-I group, Dilicacy, Emotionality, and Lack of Confidence from the D-C group, Psychogenic anxiety, and Somatic Symptoms of Anxiety from the Anx group, Self-sufficiency, and Ego-centricity, and Ego-maturity from the As-Ce group. Most of the factors corresponded to those which were extracted from the first trial inventory. Inventory for Practical UseEighty seven items loading high onto the 10 factors (excepting Self-sufficiency) were selected, and a third inventory was composed for practical use. This inventory was administered to 1262 subjects, including junior high pupils, senior high school pupils, and college students. They were divided into two groups; one the younger group and the other the elder group. Scores of traits (factors) were correlated and factor analyzed for both groups separately. Four second order factors were extracted for both groups. In regard to the patterns of factor loadings, the four factors of the one group showed close resemblances to the four factors of the other group, The factors were interpreted as follows; 1. Hypochondria. 2. Ego-tonicity and Emotionality. 3. Surgencydisurgency. 4. Thinking introversion and extraversion.
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