Psychometric Values Research Articles

Discerning the latent structure of hypothetical psychosis proneness through admixture analysis

The application of psychometric procedures to a normal population sample to detect individuals with increased liability for schizophrenia is a useful methodological adjunct to the traditional genetic high-risk strategy. A necessary and reasonable step in the process of establishing the utility of a viable psychometric index of schizotypy is the formal investigation of the latent structure of psychometric values. The present study used admixture analysis to examine the distribution of scores on the Perceptual Aberration Scale (PAS), an objective measure of hypothetical psychosis-proneness, in a randomly ascertained sample of 18-year-old university students ( n = 707). We applied parametric methods that assumed normally distributed component distributions; viewed in this context, our results are hypothesis-generating and not definitive confirmation of specific hypotheses. Within our methodological framework, the results provide strong evidence for the commingling of normal distributions, even after allowing for unequal variances across components and after removing skewness. The overall distribution of power-transformed data is consistent with the existence of three qualitatively distinct classes of PAS responders. We discuss our results in light of Meehl's model of schizotaxia, a “mixed model” of inheritance of liability to schizophrenia, and we review the methodological implications of our findings for future research.

Depth dimension. A psychometric approach and some clinical data.

A psychometric scale based upon phenomenological descriptions was constructed for approaching the emotional depth dimension of personality. Some nosological groups of endogenous psychoses tested in the frame of a controlled follow-up study were characterized by psychometric values which might be discussed both in relation to prepsychotic personality and to course of illness.

Motion direction identification in random cinematograms: a general model.

The cinematograms of 12 two-state elements arranged in the clock positions in space and in a sequence of adjacent 100-ms frames in time were used as stimuli. Some positions in each frame (or all 12 of them) could be labeled as "domain" ones, and every element that was T frames and S positions (clockwise or counterclockwise) apart from a domain element could repeat the latter's state with probability P. The probability of the rotation direction identification was obtained as a function of T, S, P, number of frames, and the domain positions selection scheme. A generalized version of the reversed phi phenomenon was obtained: if P less than .5, then the psychometric value lies below .5 level. All the data can be accounted for by a simple model according to which the choice of direction is based on the counts of the different types of dipoles, each type being characterized by the probability and the weight of its count: In most situations all dipoles but the shortest ones (connecting the neighboring elements of successive frames) can be ignored.

Psychophysical Relationship of Image-Quality Characteristics of Motion-Picture Color Films

The results of a psychometric evaluation of image-quality characteristics in a series of motion-picture color films are compared with the data obtained by physical measurements of corresponding image-quality parameters. Implications of psychometric scaling of image-quality characteristics by means of a paired-comparisons method are discussed. The psychophysical relationship between measured quantities — RMS granularity, FEM, and MTF — and the psychometric scale values were examined by a regression analysis technique. The relation between scale values for graininess and granularity parameters appears to be linear.

The Holtzman Inkblot Technique: a review.

After brief description of the rationale, construction, and structure of the Holtzman Inkblot Technique, this study critically reviews 10 years (19591969) of research with this instrument. An impressive body of positive findings is in evidence, but many more studies are needed in most areas covered by this review. The various technical refinements and extensions of this instrument that have been produced should facilitate the appearance of much needed future research. The dearth of relevant studies renders an evaluative comparison with the Rorschach impossible at this time. Implications of certain issues raised by R. Schafer in 1948, M. D. Ainsworth in 19S4, and R. Holt in 1968 in relation to Rorschach validity studies are discussed in reference to research with the Holtzman technique. Although Holtzman recently provided summaries of research on the Holtzman Inkblot Technique (Holtzman, 1966, 1968), his presentations were not evaluative, not much information was given concerning the designs of the studies reviewed, and number of studies were not included. The present review (a) presents brief description of the rationale, construction, and structure of this instrument; (b) provides an evaluative review of the literature from 19S9 to 1969, inclusive; and (c) discusses the general character of this research in light of previous criticisms of Rorschach validity studies. It should be noted that this review attempts to be primarily informative and secondarily evaluative. It is hoped that the inclusion of more than the usual amount of descriptive material with respect to specific studies will facilitate the future appearance of much needed additional research that is indicated in several areas covered by this review. The authors of the Holtzman Inkblot Technique (HIT) have described their goal as one of developing a new inkblot technique having scores of demonstrated psychometric value while still preserving the rich, qualitative

Nonlinear Relations of Psychometric Scale Values to Chromaticity Differences*

Psychometric scale values for color differences are correlated with physically measured chromaticity differences by use of a formula which postulates that the scale values are proportional to some power, less than unity, of distance in a subjectively isotropic, projective transformation of the CIE chromaticity diagram. Exponents ranging from 0.38 to 0.80 are reported. Eleven to 37% smaller root-mean-square errors of fit to psychometric scale values are obtained with the nonlinear hypothesis than with a linear hypothesis.

New method for the assignment of psychometric scale values from incomplete paired comparisons.

The principle of least squares is applied to the selection of an optimum set of n response values, or of (n−1) basic response differences, corresponding to n stimuli, from m observed response differences provided by the paired-comparison method of psychometric measurement. This method of selection is shown to be the most appropriate generalization, to the case of a usable but incomplete set, i.e., with n-1≦ m<12n(n-1), of observed response differences, of a corrected form of the algorithm of J. P. Guilford. Unlike the Guilford algorithm, however, direct application of the least-squares principle implies response values which are independent of the a priori ordering of the n stimuli, even in the incomplete-set case.