Observers’ sensitivity to dynamic anomalies in collisions

The present study examined observers’ ability to discriminate canonical and dynamically anomalous collisions that were presented in either frictionless or frictional systems. Whereas previous research has provided qualitative demonstrations that dynamic information can be extracted from visual events, the current study provides a parametric assessment of observers’ sensitivity to dynamic invariants. Our findings indicate that observers are competent when viewing both familiar, terrestrial (frictional) systems and unfamiliar but computationally simpler, 0-G (frictionless) systems. Thus, our sensitivity to these dynamic invariants in visual events is robust in natural systems whose dynamic properties differ from those of the environment in which we evolved and developed.     

Temporal manipulation of stimulus patterns using the Apple II: Tachistoscopic and part presentation

A technique is described in which line-drawn pictures can be rapidly interlaced, allowing for sequential part presentation or tachistoscopic presentation on the Apple II. This is accomplished using a two-stage process in which the pictorial stimuli are converted into machine code data files and then used to create a rapidly changing display consisting of two or more line drawings. The latter stage could be accomplished in less than 2 msec but is limited by the frame time of the monitor (17–20 msec).     

Difficulty and familiarity norms for 192 single-solution word fragments

Normative data are presented for the probability of successfully completing 192 single-solution word fragments. Normative data on the familiarity of college students with the solution words are also given, along with estimates of word frequency from existing norms. Regression analyses were performed in order to predict fragment completion difficulty from familiarity, frequency, and several structural characteristics of the fragments. Familiarity, whether or not first and/or last letters appeared in the fragment, and the ratio of letters to missing letters in the fragment were included in the regression equation as significant predictors of difficulty for this fragment set.     

Learning and motivation: Computer simulations of the Rescorla-Wagner,Solomon-Corbit,and Schull models

A suite of programs is described for simulating the Rescorla-Wagner (1972) model of associative learning, the Solomon and Corbit (1974) opponent-process theory, and Schull’s (1979) extension of the latter. The programs are written for the Commodore 64 computer.     

Containment theory and juvenile delinquency: a reevaluation through factor analysis

All seven variables of containment theory were operationalized for questionnaires. Data were collected from 677 adolescents in a variety of high schools and correctional institutions, and divided into categories by race and sex. Factor analysis indicated that the structure of the relationships among the seven containment variables and delinquency was substantially different among black females.     

Parent-child communication about sex and young adolescents' sexual knowledge and attitudes

Previous studies indicate that adolescents whose parents talk to them about sex tend to be less sexually active and more likely to use an effective means of contraception. This study sought to determine the relationship between parent-child communication about sex and young adolescents' reproductive and contraceptive knowledge and sexual attitudes. Twenty-two 12- to 14-year-olds and their parents completed sexual-knowledge, sexual-attitude, and contraceptive-choice questionnaires. Families were divided into high-communication and low-communication groups. There were no significant differences in the sexual knowledge, attitudes, or contraceptive choices of the children in the two groups, but the correlation between parents' and children's sexual attitudes in the high-communication group was significantly higher than that of the low-communication group. Although this was a correlational study, it seems likely that the similarity in sexual values was the result of parent-child discussion about sex.     

Prevalence of DSM-III conduct and adjustment disorders for adolescent psychiatric inpatients

The prevalence of DSM-III conduct and adjustment disorders in two adolescent psychiatric facilities, both located near large U.S. cities, was investigated. Overall, 31.6% of the adolescent inpatients were conduct disordered while 12.5% were adjustment disordered. The conduct disorders were primarily "aggressive" subtypes suggesting that this characteristic may influence hospitalization and diagnostic decisions. Such data on prevalence assists future treatment planning, allowing anticipation of case loads.     

Students' attitudes toward university health services

This study measured students' attitudes toward a university's student health services (SHS) and identified factors that were related to their attitudes. A questionnaire surveying students' attitudes was administered to a sample of 150 students at the Oxford Campus of the University of Mississippi. Analysis of the data revealed that students' attitudes had a statistically significant correlation with the following variables: perceived medical care cost, amount of health information/education received during medical encounters, time spent in the waiting room of the SHS, sex of the student, and income of the student. There was no significant relationship between attitude and age.     

The effects of service activities on adolescent alienation

This research evaluated the effects of involvement of adolescents in community service activities on levels of alienation. It was proposed that alienation could be reduced through the implementation of a model which utilized community service activities to facilitate adolescent access to adult society, development of responsibility, collaborative and cooperative work, and control over planning and outcomes. It is suggested that adolescent involvement in service activities can produce positive benefits, among which are reduced levels of alienation, improved school behavior, improved grade point average, and acceptance by the adult community. These findings also suggest that females respond more positively to school when allowed to problem-solve collectively and collaboratively.