Texture gradient effectiveness in the perception of surface slant

To assess the development of monocular slant perception as well as the relative effectiveness of different sources of information, children in first, third, and fifth grades and college adults were asked to make judgments of surface slant on the basis of monocular texture gradient information. Accuracy of judgment increased with increasing age. In addition, differences in gradient effectiveness were found. Compression gradients were relatively ineffective sources of information, whereas perspective and multiple gradients resulted in greater accuracy. The results suggest limitations on the specificity of certain forms of gradients.     

Some psychometric correlates of behaviour in India and Canada(1)

A number of questionnaires, measuring category-width, risk-taking propensity, tolerance of ambiguity, world-mindedness and authoritarianism, were administered to samples of university students in India and Canada. The results are consistent with previous investigations and indicate that the Indians, as contrasted with the Canadians, prefer narrow categories, choose conservative risks, are less tolerant of ambiguity, are more authoritarian and, if attending a Hindu College, are less world-minded. The relationship of these orientations to other variables such as achievement motivation are discussed and the importance of antecedent child-rearing practices is noted.     

MODIFICATION OF THE EXCESSIVE INAPPROPRIATE CLASSROOM BEHAVIOR OF TWO ELEMENTARY SCHOOL STUDENTS USING HOME-BASED CONSEQUENCES AND DAILY REPORT-CARD PROCEDURES1

Two experiments investigated home-based reinforcement contingencies to control excessive behavior in normal classrooms. Subjects were, respectively, a 12-yr-old fifth-grade boy and a 9-yr-old fourth-grade boy, each in a separate classroom and with a different teacher. Following baseline observations in which observers recorded several categories of student behavior and teacher-student interaction, separate conferences were held including parents of the two children, the principal, teachers, and experimenters. A daily report-card procedure was agreed on, stipulating a one-day suspension from school following three successive “undesirable” daily report cards as well as the supervision of home-based privileges and other reinforcers usually contingent on satisfactory daily reports. Measurements of daily rates of teacher attention indicated no important change in this variable throughout the various experimental conditions. The daily report procedure significantly reduced disruptive classroom behavior. In a second experiment, a teacher-operated timer cued her own time-sample observations. Reliability measures revealed that the teacher could accurately measure the child's behavior while she was teaching the class. The procedure was ultimately successfully expanded to the teacher's total contact hours each day.     

Latent roots of random data correlation matrices with squared multiple correlations on the diagonal: A monte carlo study

In order to make the parallel analysis criterion for determining the number of factors easy to use, regression equations for predicting the logarithms of the latent roots of random correlation matrices, with squared multiple correlations on the diagonal, are presented. The correlation matrices were derived from distributions of normally distributed random numbers. The independent variables are log (N–1) and log {[n(n–1)/2]–[(i–1)n]}, whereN is the number of observations;n, the number of variables; andi, the ordinal position of the eigenvalue. The results were excellent, with multiple correlation coefficients ranging from .9948 to .9992.This research was supported by the Office of Naval Research under Contract N00014-67-A-0305-0012, Lloyd G. Humphreys, principal investigator, and by the Department of Computer Science of which Richard G. Montanelli, Jr., is a member.     

Transformations. II. Latency of generation

This study tested the hypothesized relationship between the rules of sentence transformation and preresponse processing time in a short-term memory and transformation task. The transform instruction was placed either before or after the stimulus sentence, and verbal responses were made with immediate or delayed auditory feedback. The data showed conclusively that the amount of processing required by different grammatical transformations does not relate, to the theoretical linguistic derivation, even when transformations are grouped into an ordinal ranking of difficulty rated by the number of nominal transform rules required. An instruction prefix facilitates information processing and interacts with the grammatical task. Sentence generation was retarded significantly by the imminent onset of delayed auditory feedback. This effect of imminentDAF appears to be a new finding.     

Transformations. I. The effect of DAF on sentence generation

A hypothesis based on the psycholinguistic derivation of sentences was tested. The task required that sentences temporarily stored in memory be transformed and spoken with delayed auditory feedback. An instruction to repeat the stimulus sentence verbatim or grammatically transform it was placed either immediately before or immediately after the sentence. Two measures of interference were obtained based on the syllable rates for the response times. The different grammatical forms showed significant variation in the amount of interference, but the amount of interference appeared to relate primarily to the length of the transformed sentence rather than to its derivational complexity. Interaction between the position of the instruction and the sentence generation task is discussed in terms of the underlying memory functions involved. A further test was proposed.     

Positive contrast following gradual and abrupt increases in reward magnitude using delay of reinforcement

In Experiment 1, rats were given a 1-pellet reward for 48 preshift trials. During a subsequent 20-trial postshift phase, one group was shifted to a 12-pellet reward on Trial 1, a second was shifted on Trial 11, and a third was given 1 more pellet each trial and then 12 pellets for the last 10 trials. The speeds of all three groups increased to a level above that of a control group given a 12-pellet food reward throughout training (positive contrast). In experiment 2, rats were shifted from 1 to 12 pellets either gradually or abruptly following either abbreviated training (9 trials) or extended training (20 trials). One group of control subjects received 12 pellets throughout training. The results revealed a positive contrast effect for gradually shifted subjects following extended training but not following abbreviated training. The abrupt shift procedure produced positive contrast following abbreviated training but only a marginal effect following extended training. These results indicate that, contingent upon the amount of preshift training, either gradual or abrupt reward increases may produce positive contrast.     

Wilhelm Dilthey: Forerunner of humanist social thought

Humanist social thought is as a meadow in the forest of positivist science. Much of this space was cleared by Wilhelm Dilthey, not only through his attack on the fundamental assumptions of positivism, but also through his formulation of a critical method by which the works of free human consciousness could be understood. The first tenet of positivism is that the world is made up of ‘out there’ objectively knowable ‘facts’. Dilthey undercut this notion by asserting that the subject matter of the human studies was not mere facts of nature, but rather objectified expressions of the human mind. The second central assumption of positivism is that these facts are explainable or determined by general causal laws. In contrast, Dilthey asserted that, while we can explain the natural world, human action must be understood through an interpretive rather than a causal logic. In demonstrating and specifically describing such an interpretive procedure, Dilthey provided an epistemological and methodological grounding fur a humanistic science of the person and of the social world. His ideas illuminate the works even of his critics and his influence, though largely unacknowledged, continues to be widespread in all the human studies.