MODELING PROBABIUSTIC CATEGORIZATION DATA:

Abstract— In probabilistic categorization tasks, the correct category is determined only probabilistically by the stimulus pattern Data from such experiments have been successfully accounted for by a simple network model, but have posed difficulties for exemplar models In the present article, we consider an exemplar model, CLEM (concept learning by exemplar memorization), which differs from previously tested exemplar models in that exemplar traces are assumed to be stored only when the subject has guessed or made a classification error Fits of CLEM to both learning and test data were comparable to those of the network model, and better than those obtained for a version of CLEM in which encoding was independent of the subject's response The implications of these results for the processes underlying classification decisions are discussed.     

MODIFICATION OF ACTIVITY LEVEL THROUGH BIOFEEDBACK AND OPERANT CONDITIONING1

The biomotometer, an electronic device that simultaneously measures activity and provides auditory feedback to the subject, was used in combination with material reinforcers in two experiments attempting to modify activity level in children. In the first study the activity level of an 11-year-old highly active boy was decreased below mean baseline during conditioning in a classroom setting. His level of activity returned to baseline when feedback was withdrawn. In the second study, activity level of a 10-year-old hypoactive boy was increased over mean baseline level during conditioning in a free-play setting, and returned to slightly below baseline during five extinction trials. Results of these studies indicate that the biomotometer is a useful instrument for modification of activity level.     

Activity level: A comparison between actometer scores and observer ratings

Activity level of 13 boys (aged 9–13) from a day hospital program was measured using actometers in classroom, gym, woodshop, and group therapy settings. Ratings of Ss' activity were obtained from mothers using the Werry scale, and from six clinical staff familiar with the Ss using the Davids scale. It was predicted that activity ratings would have situationally specific relationships with actometermeasured activity level according to the rater's opportunities for observation. Comparisons between measures indicated that all clinical staff ratings correlated significantly with actometer activity in the classroom (r=.49 to r=.73), while mothers' ratings correlated significantly with actometer activity in gym (r=.67), and woodshop (r=.77), and with overall activity (r=.65), a combined measure derived from actometer scores in the four conditions tested. Five of six clinical staff raters showed significant interrater reliability (r=.58 to r=.83). Results are discussed in terms of their implications for solution of current problems in assessment of activity level and hyperactivity.     

Counseling,Risk Taking,and the Learning Process

It is crucial that counselors recognize that the problem-solving process that occurs in a counseling situation is synonymous with classroom learning. It is imperative that counselors understand the nature of the problem-solving process and how to guide and nurture this process, to increase their own effectiveness and their counselees' growth. Understanding the concepts of risk taking and intrinsic and extrinsic reinforcement and their relationships to the counselees' problem-solving processes will allow counselors to establish their own counseling approaches and respond to the counselees' learning needs. Jerome Niles is an assistant professor of curriculum and instruction at Virginia Polytechnic Institute and State University in Blacksburg. Marianne DeVoe is an assistant professor of educational foundations at the University of Wyoming in Laramie.     

Intelligence tests on trial: An “interview” with judges Robert F. Peckham and John F. Grady

The issue of culturally biased intelligence tests has been heard in two federal courts. Judge Robert F. Peckham, in the Larry P., et al. v. Wilson Riles, et al. case, ruled that intelligence tests were culturally biased. In contrast, Judge John F. Grady, in the Parents in Action on Special Education, et al. v. Joseph P. Hannon, et al. case, ruled that intelligence tests were not culturally biased. A mock “interview” based on the judges' written opinions, shows similarities and differences in their approach to various issues involved in the trials.     

Relations between nutrition and cognitive performance in Egyptian toddlers

Two relatively unexplored questions--which specific components of chronic mild child malnutrition are associated with specific behavioral and cognitive deficits and do psychosocial child rearing factors moderate the nutrition-development relationship?--were investigated in a longitudinal study involving 153 toddlers from the Egyptian village of Kalama. Beginning at study entry at age 18 months and continuing until 30 months, food intake information was obtained for 2 consecutive days each month. During the same period, researchers visited the homes twice a month to observe both toddler behavior and caregiver styles. Finally, standardized infant development tests were administered at 24 months and 30 minutes and the capacity for exploratory, symbolic play was assessed. Specific components of nutritional intake at 18-23 months of age were confirmed to be uniquely related to specific developmental outcomes at 24 months of age. Changes in toddler intake from 18-30 months also predicted 30-month cognitive performance. At 24 months, general mental competence was associated positively with fat intake, total kilocalories, and total protein intake while symbolic play capacity was related only to total protein intake. Significant increases in predictive variance occurred when the model was expanded to encompass caregiver behaviors as well as nutritional factors. For example, when nonverbal response to child vocalizations was used as the environmental measure, there was evidence of both coactive and synergistic interactions for comparisons involving cognitive development indicators. For symbolic play, an increase in predictive variance was found when the model included the multiplicative interaction of animal kilocalories by nonverbal response to vocalizations. Also observed was a buffering effect against poor psychosocial rearing conditions given the presence of adequate nutritional intake. These findings suggest the feasibility of multidimensional risk profiles, the provision of specific nutrients targeted at specific deficits, and multidisciplinary interventions.     

A validational note on the revised Socialization Scale of the California Psychological Inventory

The revised (1987) Socialization Scale of the California Psychological Inventory was studied in a sample of 121 delinquent and nondelinquent males to determine if the revised scale, compared to the original version of the scale (1957), could differentiate among a group of nonoffenders and a comprehensive typology of offenders. Results of an ANOVA and product-moment correlations provided significant and considerable support for the discriminability of the revised So Scale. Obtained results indicate that the revised instrument can differentiate offenders from nonoffenders to about the same, or a greater, degree than the original scale.     

Ethnicity and bender visual motor gestalt test performance

This study compared differences in the Bender-Gestalt mean error scores of the 1,938 black, Hispanic, and white children in the System of Multicultural Pluralistic Assessment (SOMPA) standardization sample. A two-way between groups unweighted means ANOVA was performed on the error scores for the seven age groups and for the three ethnic groups. Significant differences were found for both main effects. Black children performed lower than (a) white children at every age level and (b) Hispanic children at all except one age level. Hispanic children performed similarly to white children at all except two age levels. Results support those reported by other investigations, but do not offer any clues to account for the findings.