THIS brief paper is not an exhaustive study of the traits differentiating masculinity and femininity. Terman and Miles (10) have provided the definitive report in this area. Our present study is primarily an empirical evaluation of: (a) the degree to which four different MF tests agree and (b) their respective capacities to distinguish, i.e., separate into the anticipated dichotomy, between men and women. A third outcome of this analysis, arising from the necessary discussion of the tests themselves, will be a useful summarization of some of the types of items demonstrating utility in characterizing sex differences.The four masculinity-femininity tests examined are the MF scales derived from each of the following: (a) Strong's Vocational Interest Blank for Men, Form M (9) ; (b) Kuder's Preference Record, Form BM (6) ; Hathaway and McKinley's Minnesota Multiphasic Personality Inventory, Group Form (2 and 3) ; and (d) Heston's DePauw Adjustment Inventory (4). The selection of these particular tests for MF analysis was largely fortuitous, i.e., the data for these specific tests were readily accessible from the records of counselees enrolled in the third annual Educational Guidance Clinic under the writer's direction at DePauw University in June, 1947. This clinic, described elsewhere (5), provided the opportunity to collect the MF scores on these four scales under certain advantageous conditions. First, the tests were all taken within a span of two or three days, thus essentially eliminating the intervening lapseof-time factor which often proves troublesome in comparison of such tests taken at different times and under differing conditions. Second, since the subjects were counselees who paid a fee to participate in an educational guidance opportunity, we can fairly assume the tests were approached under optimum at SIMON FRASER LIBRARY on May 29, 2015 epm.sagepub.com Downloaded from 376 EDUCATIONAL AND PSYCHOLOGICAL MEASUREMENT conditions of sincerity, honesty, and general motivation. This latter point is important because it has been demonstrated that MF scores are easily faked, if the subjects have been so requested (10, page 77). The four MF tests thus available permit a particularly fortunate chance to evaluate MF scales based on dissimilar categories of items. Two of the tests, the Strong and the Kuder, are composed fundamentally of items measuring interests. The MMPI (used hereafter to denote the Minnesota Multiphasic) is composed of iterest items and personality questions. The DePauw scale has items designed to elicit feelings and emotions of a more subjective nature, and thus shows similarity to the personality items of the MMPI. An obvious hypothesis, then, at the outset, is that the two interest tests should prove more closely related as one pair of MF scales. The two so-called personality tests should form another pair of agreeing MF scales, to the extent that personality questions enter into their item content. The determination of the extent of these correlations