Imputation of missing categorical data by maximizing internal consistency

This paper suggests a method to supplant missing categorical data by reasonable replacements. These replacements will maximize the consistency of the completed data as measured by Guttman's squared correlation ratio. The text outlines a solution of the optimization problem, describes relationships with the relevant psychometric theory, and studies some properties of the method in detail. The main result is that the average correlation should be at least 0.50 before the method becomes practical. At that point, the technique gives reasonable results up to 10–15% missing data.We thank Anneke Bloemhoff of NIPG-TNO for compiling and making the Dutch Life Style Survey data available to use, and Chantal Houée and Thérèse Bardaine, IUT, Vannes, France, exchange students under the COMETT program of the EC, for computational assistance. We also thank Donald Rubin, the Editors and several anonymous reviewers for constructive suggestions.     

Visually perceived eye level: changes induced by a pitched-from-vertical 2-line visual field.

The physical elevation corresponding to visually perceived eye level (VPEL) changes linearly with the pitch of a visual field. Deviations from true eye level average more than 0.5 times the angle of pitch over a 65 degrees pitch range. A visual field consisting of 2 dim, isolated vertical lines in darkness is more than 4/5 as effective as that of a complexly structured visual field; 2 horizontal lines have a small and inconsistent effect. Differences in influence on VPEL between pitched-from-vertical and horizontal lines were predicted from an analysis that extracted differences in retinal perspective resulting from changes in pitch. The Great Circle Model (GCM), based on a spherical approximation to the erect, stationary eye, predicts the present results and results of 8 other sets of experiments. The model treats the influence of a single line on VPEL as systematically related to the elevation of the intersection between the great circle containing the image of the line and the central vertical retinal meridian; generalized GCM combines visual inputs with inputs from the body-referenced mechanism and maps onto the central nervous system.     

儿童理解数量词“几个”、“很多”的发展特点

本工作采用了一种研究儿童理解不精确量词的经验方法,初步探讨了四岁至十岁儿童理解数量词“几个”、“很多”的发展特点。结果提示:儿童对两个数量词的理解与实验给出的论域(数量范围)关系密切;数量词“几个”比“很多”较早被年幼儿童所理解。其发展特点:四岁至十岁儿童在[0,10],[0,20]范围上,均能较好理解“几个”;六岁以上儿童只能在[0,10]的范围上理解“很多”的词义;四岁儿童则表现出把“很多”与“全部”混同。     

Assessing the acceptability of staff management procedures to direct care and supervisory staff

Direct care and supervisory staff in five residential training programs for persons with mental retardation in North Dakota rated the acceptability of six staff management procedures. Overall, staff rated “Instructions”, “Instructions and Modeling”, “Feedback and Praise”, and “Instructions, Feedback, and Praise”, as significantly more acceptable than “Self-Management” and “Self-Management, Feedback and Praise”. There was a significant group by treatment interaction in which supervisors and direct care staff had significantly different acceptability rating for four of the six procedures. The results were further analyzed by group and implications and future research are discuessed.     

Multilevel models in developmental psychological research: Rationales and applications

The armoury of statistical techniques has recently been enhanced with the multilevel model for longitudinal data. The present article explains the multilevel model for longitudinal data to the statistically non-sophisticated reader. It shows how the model relates to the five rationales of longitudinal research, as they were put forward by Baltes and Nesselroade (1979). In addition, it shows how the model matches Wohlwill's methodology of developmental functions. To elucidate the model further, three applications are given. The applications pertain to the development of children's sleeping duration during the first 18 months of life, the effects of early hospitalization on the daily frequency of crying, and the developmental relationship between social and solitary play.     

Three-space inference from two-space stimulation

Oblique contours sloping at 30° with respect to the horizontal were presented alone, in combination to form chevrons, or with a vertical line to form arrowhead or Y patterns; they were projected onto a screen in the frontal parallel plane and viewed from positions that gave viewing angles of 90° (normal to the screen’s surface), 53°, or 34°. The perceived orientation of the contours, as assessed by a movable arm that the subjects set to be parallel to the obliques, changed monotonically as a function of viewing angle. The change was as great for single obliques as for combinations of obliques within the chevron, arrowhead, and Y patterns. The results of Experiment 1 were extended in Experiment 2, in which obliques at 30° and 50° with respect to the horizontal were presented singly or in combination as chevron patterns. It is argued that the results of both experiments indicate that single two-space oblique lines are immediately interpreted as lying in three-space and that the changes in perceived orientation are a consequence of this perceptual inference.     

Perceptual selectivity for color and form

Three visual-search experiments tested whether the preattentive parallel stage can-selectively guide the attentive stage to a particular known-to-be-relevant target feature. Subjects searched multielement displays for a salient green circle that had a unique form when surrounded by green nontarget squares or had a unique color when surrounded by red nontarget circles. In the distractor conditions, a salient item in the other dimension was present as well. As an extension of earlier findings (Theeuwes, 1991), the results showed that complete top-down selectivity toward a particular feature was not possible, not even after extended and consistent practice. The results reveal that selectivity depends on the relative discriminability of the stimulus dimensions: the presence of an irrelevant item with a unique color interferes with parallel search for a unique form, and vice versa.     

TREATING WOMEN AS SEX-OBJECTS

In this paper we have two related aims. First, we aim to present an account of what it is to treat women as sex-objects.¹ Like other philosophical writers in the field, we hold that the central idea in an account of such treatment is the failure to treat women with proper respect in sexual behavior. This idea has been cashed out in terms of using,² and in terms of dehumanization or failure to accord equal rights to freedom and welfare.³ However, we believe that there is a central deficiency in most such philosophical accounts of treating women as sex-objects, namely, a failure to outline in any detail a theory of interpersonal norms so that one can grasp in more concrete terms what it is to avoid treating a woman as a sex-object. We aim to rectify this deficiency by presenting a model of interpersonal norms based on the work of the social psychologist Chris Argyris.⁴