Salt taste detection: an R-index approach to signal-detection measurements

The R-index approach to the signal-detection P(A) index of sensitivity was used to measure taste sensitivity to NaCl solutions. The R-index is the predicted probability of the correct choice of a signal, for a given signal-noise pair. For flow-wise and sipwise presentation, R-indices did not fluctuate significantly, provided subjects could not see the stimuli yet to be presented, indicating a lack of systematic sensitivity drift. The simultaneous measurement of more than one signal strength with reference to a common noise stimulus was seen to be a viable and sensitive procedure. Comparison of flow-wise and sipwise presentation of stimuli using R-indices, indicated that the former elicited greater subject sensitivity to NaCl taste.     

Intelligence differences and conceptual judgement

Summary Studies of gifted children were recently reviewed by Vernon, Adamson, and Vernon (1977). These studies can be said to fall into three main categories, those concerned with the identification and education of such children, e.g., Ogilvie (1970), the psychometrically analysed structure of their abilities, e.g., Guilford (1967) and the factors contributing to success or creativity among those of high IQ, e.g., Terman (1930), Torrance (1969) and Wallach (1970). Few experimental studies have been attempted in this area despite the current interest in the relationship between intelligence and cognitive processes. The experiments reported here are intended to initiate an exploration of the effect of intelligence differences on the conceptual structure of different groups of children. The task selected as a basis for such an investigation was that developed by Collins and Quillian (1969), and taken further by Schaeffer and Wallace (1970). Pairs of words and pairs of pictures chosen from four hierarchically ordered categories were presented to children of average or of high intelligence for comparative classification. Subjects were asked to say whether or not the two items in a pair belonged to the same or different conceptual categories, and to press buttons accordingly. Despite a marked IQ difference, the two groups did not differ in the speed with which they judged picture pairs to be the same or different, but the gifted children were significantly faster in judgements based on presented word pairs. Supplementary studies attempted to determine the source of the interaction in terms of perceptual, motor response, or decision functions.     

Assessment of human obesity: The measurement of body composition

The most common methods of assessing degree of obesity in humans are reviewed. These include anthropometry, somatotyping, bodyweight, skinfold calipering, densitometry, and several nondensitometric procedures. The evidence suggests that bodyweight may often be an unreliable and invalid index of obesity. The parameters influencing its inaccuracy are discussed. These include age, height, sex, muscularity, and degree of obesity or amount of recent weight loss. The most reliable and valid measures of human bodyfat are generally the most complicated and impractical. Compromise assessment procedures involving nonintrusive measurement of subcutaneous fat and selected anthropometric dimensions may offer an incomplete but welcome improvement over sole reliance on bodyweight as an index of obesity.     

A study of orientation errors in response to Kohs-type figures(1)

In order to elucidate the nature of the orientation errors encountered when subjects are required to reproduce Kohs-type figures, subjects drawn from a culture where such errors are reported to be relatively common were required to reproduce orientation of simple figures. It was found that the responses made in the case of square figures showed a definite drift towards a “stable” orientation; the drift observed in the case of circular stimuli was too weak to permit an unambiguous interpretation. The relevance of these data to previous data on cross-cultural differences in responses to Kohs-type stimuli is briefly examined.     

Peer tutoring among elementary students: educational benefits to the tutor

To determine whether tutoring might be academically beneficial to the tutor, this study investigated the acquisition of spelling words by three elementary students in a peer tutoring program. The experimental design allowed a simultaneous comparison of each child's gain in performance on comparable word lists on which the child tutored another child, was tutored by another child, or neither gave nor received tutoring. The children's spelling improved nearly an equivalent amount on those words on which they tutored another child as on the words on which they were tutored; no such change was noted on the words on which they neither gave nor received tutoring. These findings, that peer tutoring is profitable for the tutor as well as the tutee, provide a basis for recommending peer tutoring as one method of individualizing education.     

Community applications of instructional technology: teaching writers of instructional packages

A community education program, to develop a variety of performance competencies in large numbers of neighborhood residents, requires a technology for preparing learning units administerable by community members themselves. The effects of a writing manual, designed to teach nonprofessionals to prepare such instructional packages, were analyzed in two experiments. Experiment I employed a multiple-baseline design across three university student trainees. The results showed that appropriate program writing increased by 75% after completion of the manual. The results of Experiment II, with two low-income neighborhood residents serving as trainees, showed that packages produced by trained writers resulted in a greater increase in skill activities than sets of training stimuli produced by untrained writers.