A comparison of multiple versus single examples of the correct stimulus on task acquisition and generalization by persons with developmental disabilities

In teaching discriminations to persons with retardation, we often presume we will improve acquisition and generalization if we use multiple examples of boththe correct and incorrect stimuli. Two experiments were conducted to test this hypothesis. In the first experiment, 7 persons with moderate retardation learned to discriminate between functional words under two conditions. In one condition, Multiple Example of S- Only,1 example of the correct stimulus (S+) and 10 examples of the incorrect stimulus (S-) were used during acquisition. In the other condition, Multiple Examples of S+ and S-,10 examples of the S+ and 10 examples of the S- were used. Results showed that the condition which presented only a single example of S+ was superior 16 times and inferior 4 times during acquisition, generalization, and maintenance. A second experiment was conducted to (a) replicate the methodology and procedures in Experiment 1 with different participants, (b) determine whether the results were replicable, and (c) obtain efficiency data. Results replicated the findings of the first experiment. The condition which presented only a single example of S+ was superior on measures of (a) trials to criterion, (b) percent correct during acquisition, and (c) minutes to criterion. On measures of generalization, the two conditions were relatively equal. Thus, the condition which presented only a single example of the correct stimulus was more efficient and was just as effective in generalization as the condition which presented multiple examples of both the S+ and S-. These surprising results were discussed in terms of stimulus control, why students performed just as well during generalization when only one example of the S+ was used, why acquisition was also poorer for this condition, and how future studies might address these points.     

The empirical study of teenage work: A behavioral code for the assessment of adolescent job environments

Policy recommendations that adolescents supplement their experience in school with experience in the workplace have been made in the absence of objective data on the nature of most adolescents' activity on the job. This paper presents a coding system for chronicling a variety of microbehaviors in sequence, as they occur, in adolescent job environments. Three elements of each of approximately 100 behaviors performed by a targeted teenage worker are recorded by an on-site observer who enters appropriate code numbers into a portable event recorder: (1) the social context of the behavior; (2) the character of the behavior; and (3) the duration and concomitants of the behavior, when appropriate. Each of 97 working teenagers was observed continuously over a two hour period on the job. Interobserver agreement on the coding of worker behaviors and the social contexts in which they occurred averaged .86 and .97, respectively. In addition to its applicability in research on the effects of working on adolescent development, information obtained using the code can be helpful in the evaluation of youth employment programs, the vocational counseling of adolescents, and the validation of subjective worker reports of job attributes.     

Multifactorial assessment of bulimia nervosa

We investigated a multifactorial approach to the assessment of bulimia nervosa by means of hierarchical factor analysis. Two hundred forty-five bulimia nervosa patients and 68 patients with either anorexia nervosa or eating disorders not otherwise specified were administered a self-report battery that was organized into 21 dimensions relevant to eating disorder patients. When dimensions from this battery were subjected to hierarchical factor analysis, support for bulimia nervosa as a unique diagnostic category was obtained. However, the emergence of 3 secondary factors and 6 primary factors suggests that bulimia nervosa can also be described more complexly. The emergence of a multifactorial model of bulimia nervosa that incorporates several existing undimensional models suggests the potential for both divergent and complicated clinical presentation in bulimia nervosa patients.