Visual search for simple volumetric shapes.

Five experiments measured reaction time (RT) to detect the presence or absence of a simple volumetric shape (target) dependent on the number of display items (distractors) and their depicted three-dimensional (3-D) orientation. Experiments 1-4 examined every pairwise combination of two different simple volumetric shapes in two 3-D orientations. Conditions exhibiting "pop-out" could be predicted by differences in their two-dimensional (2-D) features. Conditions in which search was slower support previously found search asymmetries for particular 2-D features. When the distractors were a mixture of the other shapes in the same 3-D orientation, search was serial, except when the target had a curved principal axis (Experiment 5). The results suggest that these simple volumetric shapes are not processed preattentively.     

A comparison of never-hospitalized and previously hospitalized adolescents: self-esteem and locus of control.

Few empirical studies have been conducted to determine the influence of hospitalization on adolescents' psychosocial processes because younger children are regarded as more vulnerable. Therefore, the purpose of this self-report, retrospective study of 115 adolescents was to compare the self-esteem and locus of control of the never hospitalized to that of adolescents hospitalized during adolescence, prior to adolescence, and during and prior to adolescence. Although no significant differences were found, the findings raise questions about long-term effects of early experiences, especially among lower socioeconomic status youth. Also, general measures of self-esteem and locus of control may be unable to determine situation-specific effects.     

Single-word reading in college dyslexics

Recent studies of single-word processing in dyslexic populations have focused on the differential predictions made by ‘delay’ and ‘deviance’ models. Many experiments in this area have sought to determine whether the reading process in dyslexia is idiosyncratic or similar to processing in younger non-dyslexic readers. Most relevant research has, however, failed to take account of recent developments in theoretical models of reading. Furthermore, relatively little research has examined the reading behaviour of ‘highly compensated’ subjects, who achieve high-level academic qualifications despite their developmental dyslexia. The present paper examines such a population, and concludes that its single-word reading is governed by the same spelling-to-sound word characteristics as reading by other groups. The implications of the results for the deviance/delay hypothesis and for models of word naming are discussed.     

Perception of conspecific faces by budgerigars (Melopsittacus undulatus): I. Natural faces.

Perception of faces by 4 budgerigars (Melopsittacus undulatus), a species of small parrot, was studied with a same-different discrimination task. Reaction times were taken as a measure of the similarity between pairs of faces and analyzed with multidimensional scaling to reveal patterns of similarity among the faces. The perception of natural faces was tested to determine which characteristics were perceptually salient. Color, patterns of markings, darkness of the iris, and size of the pupil corresponded to the observed patterns of similarity among the faces. Differences among budgerigar faces were more salient than differences among zebra finch faces, and budgerigar faces were perceptually distinct from the faces of other avian species. The results from these experiments provide a basis for understanding the ways in which these signals function in the coordination of social behaviors.     

Sex-role attitudes,curriculum choice,and career ambition: A comparison between women in typical and atypical college majors

This study of college women examines the relationship among sex-role attitudes, curriculum choice, and levels of educational and occupational aspirations and expectations. Data for analysis are from a 1977 survey of college students enrolled in home economics and agricultural curriculums in all southern land grant colleges and universities. Results show that sex-role ideology is only weakly associated with curriculum choice but is related to career ambitions for women in sex-typical and sex-atypical areas of study.     

Asymptotic comparison of missing data procedures for estimating factor loadings

Large sample properties of four methods of handling multivariate missing data are compared. The criterion for comparison is how well the loadings from a single factor model can be estimated. It is shown that efficiencies of the methods depend on the pattern or arrangement of missing data, and an evaluation study is used to generate predictive efficiency equations to guide one's choice of an estimating procedure. A simple regression-type estimator is introduced which shows high efficiency relative to the maximum likelihood method over a large range of patterns and covariance matrices.     

Assimilation and discovery

My aim in this paper is to examine a rational discovery strategy that I call “assimilation”, the attempt to understand a new domain by systematically interpreting the items it contains in terms of an established conceptual structure. The claim that this approach can lead to important new discoveries is illustrated by considering Galileo's attempt to develop a mathematical theory of the strength of materials and his discovery of mountains on the moon.