Knowledge of the alphabet: A comparison between letter counts and subjective reports

Subjects’ estimates of the frequency of occurrence of the letters of the alphabet were compared with previously reported letter-frequency counts. The results indicated an overall good relationship between actual and judged rank, but there were consistent letter-specific under- and overestimations. These inaccuracies were not accounted for by letter versatility, first-position frequency, or order in the alphabet. There was evidence that subject-derived estimates of letter frequency were somewhat better predictors of reaction time performance on letter-processing tasks.     

Sequential item selection: Optimal and heuristic policies

This paper considers testing in which the goal is to minimize the number of test items required to establish a learner's state of ability. Focus is on optimal or near optimal selection over a well-defined universe of items or stimuli. Selection policies are determined for the case in which the items have hierarchical or partial hierarchical relationships. Derivation of an optimal policy rests upon techniques from dynamic programming. For situations in which an optimal policy may be too costly to compute, two heuristic approximations are offered. One heuristic counts the hypothetical estimates of ability that remain tenable following a response to each item and chooses the item that minimizes the expectation of that number. The other selects the item that maximizes the statistic of information.     

A user-interactive graphics-based computer system for analysis of the EEG

Computer technology provides a powerful high-resolution tool for the analysis and understanding of the electroencephalogram (EEG). A system of user-interactive graphics-based computer programs analyzing the power spectral density (PSD), coherence, and phase-angle relationships of the EEG is described, along with the mathematical algorithms used. The analytic variables inherent in coherence analysis are reviewed. These variables include choices of sampling parameters, auto- and cross-spectral algorithms, smoothing techniques, and use of the γ²(f) or γ(f) value for coherence. These variables in the analysis itself have a net interactive effect on the calculated results that often makes comparability of data across studies impossible. Thus, it is proposed that studies include a graph showing the authors’ derived coherence values for a set of standard test signals to enhance scientific communication.     

Peripheral vision: The effects of developmental,perceptual, and cognitive factors

The effects of perceptual and cognitive factors on information processing in the visual periphery were studied in 5- and 8-year-old children and in adults. Subjects judged either the similarity (Study 1) or the identity (Study 2) of geometric forms. In both studies, two forms were simultaneously presented for 20 msec at 2, 4, or 6°, with one form on either side of the fovea. Type of form and Axis of presentation were varied. Both studies demonstrated declining performance with increasing distance, poorer performance with open than closed forms, poorest performance along the vertical axis, and no major interaction of these factors with age. Greater “flattening” of the visual field was found in Study 2 than in Study 1 for all age groups. The results indicate that the parafoveal visual field is elliptical and that more difficult tasks accentuate this asymmetry. This effect of task demands on the relative flatness of the effective visual field cannot be interpreted on the basis of anatomical factors. The findings indicated striking developmental similarity in the effect of several variables on parafoveal processing and challenge the idea of greater tunnel vision in preschoolers than in adults. Further, the data suggest that perceptual and cognitive factors influence the size and shape of the effective visual field across the full age range studied.     

Visual memory and stimulus repetition effects

Recent investigations of memory for randomly configured patterns indicate that visual memory can involve distinct short-term and long-term components. The appearance of a visual recency effect that is confined to the last-presented item is believed to result from the active visualization of this item during the retention interval. Studies of the retention of familiar visual information have also suggested that the short-term effects observed are a result of active visualization. In a review of these studies, however, we argue that the effects obtained with familiar visual information are not necessarily a result of active visualization and, indeed, may not involve anything other than long-term visual memory. For example, Rabbitt and Vyas (1979) observed a visual recency effect in a serial choice reaction time task involving familiar information. That this recency effect was confined to the final item accords with the results obtained with unfamiliar visual information. However, this choice reaction time task did not require subjects to remember previous stimuli, so it is unlikely that they actively visualized them. With the case for a distinct short-term visual memory currently resting on the recency effect interpreted as reflecting a process of active visualization, this result is especially important. In the second part of the present paper, we report a series of experiments that provides an understanding of the visual recency effect in the serial choice reaction time task. We conclude from these studies that this effect is not due to visualization or to a visual trace either decaying or being overwritten by a succeeding stimulus.     

Dimensionality of women's career orientation

Two factor analytic studies were conducted in order to determine the dimensionality of women's career orientation defined by various extant measures. In Study I, 86 women employed by an insurance company responded to nine different measures of career orientation. A principal axis analysis produced two oblique factors, which were tentatively named Career Centeredness and Career Commitment, respectively. Study II sought to validate the factors found in Study I in a sample of 335 university women in various disciplines and at various class levels. Using the factor pattern from Study I as the target matrix, a restricted maximum likelihood factor analysis showed that two factors similar to those in Study I accounted for all the significant common variance. Based on both statistical criteria and psychological meaningfulness, the two oblique (r=.43) factors were again named Career Centeredness (lifestyle in which one's career is regarded as more important, time consuming, and satisfying than other aspects of life, particularly family) and Career Commitment (lifestyle involving continued employment throughout life stages regardless of financial need or competing obligations). These findings are discussed in the context of changing societal support for women's roles in business.This report is based on a portion of the first author's doctoral dissertation, supervised by the second author, done in the Department of Psychology of New York University.Both authors are currently at Merrill Lynch, 165 Broadway, New York, New York 10080.     

Construction of a tape-controlled system of presenting visual-spatial and visual-temporal stimulus patterns for use in cross-modal and intramodal matching tests

A technique of tape construction is described for use in the generation and control of all combinations of auditory-temporal, visual-temporal, and visual-spatial stimulus patterns. This technique allows the development of a set of nine tasks for testing cross-modal and intramodal matching.     

Wisconsin's Research-Through-Service Program for Superior High School Students

The Research and Guidance Laboratory for Superior Students was organized at the University of Wisconsin in 1957 to conduct longitudinal research-through-service for superior high school students. It currently involves 2,000 young people from 75 Wisconsin secondary schools. Each year faculties of cooperating schools use multiple criteria to select new ninth-grade participants. Selected students visit the Laboratory annually throughout high school for evaluation, testing, counseling, and visits to classes and professors in fields of their choice. After students come to the University, Laboratory staff members visit their schools to interview parents and meet with teachers. Laboratory activities generate many research questions concerning identification, guidance, and educational and vocational development of superior students. It is intended to continue research and follow-up of Laboratory subjects for many years after they leave high school.     

Position reversal training in the virginia opossum: Evidence for the acquisition of a learning set

To obtain an estimate of the learning ability of opossums, five tame ones were trained on a series of position reversals to a criterion. With 4 trials per day there was no consistent improvement over a series of 15 reversals. When each daily session was increased to as many trials as needed to reach criterion, errors dropped sharply, indicating the formation of a position learning set. Upon return to 4 trials per day, 3 of 4 animals continued to perform with few errors, showing transfer of learning set. Opossums do more poorly than rats on this task, which is in agreement with the relative phyletic level of the two species.