Estimation of reliability and true score variance from a split of a test into three arbitrary parts

This paper gives a method of estimating the reliability of a test which has been divided into three parts. The parts do not have to satisfy any statistical criteria like parallelism or-equivalence. If the parts are homogeneous in content (congeneric),i.e., if their true scores are linearly related and if sample size is large then the method described in this paper will give the precise value of the reliability parameter. If the homogeneity condition is violated then underestimation will typically result. However, the estimate will always be at least as accurate as coefficient and Guttman's lower bound ₃ when the same data are used. An application to real data is presented by way of illustration. Seven different splits of the same test are analyzed. The new method yields remarkably stable reliability estimates across splits as predicted by the theory. One deviating value can be accounted for by a certain unsuspected peculiarity of the test composition. Both coefficient and ₃ would not have led to the same discovery.Expanded version of a paper given at the Psychometric Society Meeting in Stanford, California, March 1974.     

Blocking the development of stimulus control when stimuli indicate periods of nonreinforcement

To learn whether prior discrimination training based on one stimulus would block learning about a subsequently added stimulus, rats were first trained to press a bar on a variable-interval schedule of food reinforcement. Occasional stimuli were presented during which no reinforcement was available. Responding became suppressed in the presence of these stimuli. Stimuli could be noise, light, or a compound of noise plus light. A group trained with noise in Phase 1, then trained with the compound in Phase 2, showed less suppression to light in a subsequent test than a group that had the same compound training in Phase 2 but only variable-interval training in Phase 1. This showed that prior training with noise blocked the development of control by light during compound training. Two further groups showed that noise training following compound training did not have the same effect on control by light.     

Behavior therapy for obesity: Booster sessions and long-term maintenance of weight loss

Following 8 weekly sessions of group behavioral self-control treatment, 75 obese women were assigned to one of five different maintenance conditions: (a) structured behavioral booster sessions held every two weeks; (b) structured behavioral booster sessions held every month; (c) unstructured nonspecific booster sessions held every two weeks; (d) unstructured nonspecific booster sessions held every month; and (e) a control group that received no booster sessions. Follow-ups were conducted at 3, 6, 9 and 12 month intervals. The study was completed in two replications. Results failed to show a significant effect of either booster session content or frequency. All groups continued to lose weight during the first three months of follow-up. Thereafter subjects in Replication 1 showed significant increases in weight over the next 9 months, whereas subjects in Replication 2 maintained their treatment-produced weight loss. The data do not support the view that booster sessions facilitate maintenance.     

Computer production of punched paper tapes for controlling experiments

Controlling experiments with paper-tape readers often requires the production of complex paper tapes. A program was written to allow automatic production and checking of complex punched paper tapes using a small computer. The user first defines the punches or punch sets to be used. He then specifies, for each successive block of tape to be punched, the number of punch sets of each type to occur and whether those punch sets should be copied in order or automatically randomized. The specified tape is then produced using a two-pass procedure, after which the tape may be automatically checked for punching errors if desired. The program has facilities for retention or modification of user commands from previous runs, simplifying the production of a large number of tapes with similar characteristics.     

Lateral word recognition: Effects of unilateral and bilateral presentation, asynchrony of bilateral presentation, and forced order of report

This experiment enquired: (1) whether right visual field (RVF) recognition superiority was greater in bilateral than in unilateral word presentation; (2) whether left field-favouring attentional or recall sets could be induced by presenting left visual field (LVF) words 20 msec prior to RVF words or by instructions to report LVF words prior to RVF words. Results showed: (1) all conditions studied yielded significant RVF superiority; (2) RVF superiority magnitude was significantly greater in bilateral than in unilateral presentation, suggesting the tenability of hypotheses that different mechanisms operate in these conditions; (3) neither earlier delivery nor earlier report of LVF words altered the pattern of RVF superiority in bilateral presentation, the later result demonstrating that differential receptive organization rather than differential recall of the two stimuli is responsible for RVF superiority in bilateral presentation.     

Attractiveness of Occupations to High School Students

Information was obtained by questionnaire from a sample of approximately 3,100 Washington high school juniors and seniors concerning career aspirations and whether they would like or dislike each of 61 selected occupations. Analysis of the responses shows (1) that a wide range of occupations, including many nonprofessional occupations, would be attractive even though 67 per cent of the boys and 59 per cent of the girls aspired to professions, (2) that students tend to reject occupations traditionally followed primarily by the opposite sex as well as a number of other occupations, and (3) that the prestige ranking of a specific occupation is not a very good predictor of occupational likes and dislikes of students. The implications of these findings are discussed.     

Representation-saving effects of prior knowledge in memory for simple technical prose

Prior knowledge of the content of a passage should reduce the effort required to encode the passage and facilitate its recall. This paper presents such effects of prior knowledge upon comprehension and memory of simple technical prose. The basic procedure was to collect ratings of the amount of prior knowledge for individual passage sentences and individual subjects, and then to determine whether these familiarity ratings predicted study time and recall. In order to validate the rating method, and also to obtain data on prior knowledge of individual facts, subjects also completed an objective test of prior knowledge of the passage facts. Three different encoding-task conditions were used: a self-paced study task, a forced-pace study task, and an incidental-learning task. A cued-recall test followed each condition. In the self-paced task, readers studied unfamiliar material longer than familiar material, but recalled at the same level regardless of familiarity. In contrast, familiarity did predict recall in the forced-pace and incidental tasks. This task specificity is explained in terms of the subjects’ encoding strategies. The basic effect of prior knowledge can be explained not only by the elaboration principle, but also by a representation-saving principle, which is presented in a simulation model that can account for the effects of familiarity on study time.     

The use of self-efficacy scaling in training student clinicians: Implications for working with stutterers

A scaling technique developed by Bandura for determining an individual's personal performance expectations (self efficacy) was applied to student clinicians working with stutterers. The self-efficacy scores of clinicians conducting treatment increased significantly while the scores of clinicians without treatment experience showed no significant change. As the student clinicians gained clinical experience there appeared to be a corresponding reduction in fear and avoidance of the treatment situation. Clinician fear concerning stuttering treatment appeared to have little relation to performance in treatment as rated by supervisors. The results indicate that self-efficacy scaling may be used to indicate clinician avoidance of working with stuttering clients.     

Alternatives in the pursuit of the predictability and consistency of persons: Stable data that yield unstable interpretations

After a review of the historical roots of current issues in personality psychology, useful sources for prediction are summarized and some current convergences in the search for coherence are identified. The value of people as expert assessors is reiterated and the stability, consistency, and predictability of behavior are distinguished as multiple issues. In the pursuit of consistency in social behavior, two major routes emerge. One route aggregates data across situations and response modes, thereby reducing the variance from those sources, and identifies the resulting stable individual differences. The second route assesses consistency from situation to situation, searches for its psychological bases, and focuses on the discriminativeness of behavior as well as its coherence. Each route serves different purposes and has value for those different goals; neither one preempts the other. Years of research on the consistency of social behavior from situation to situation have yielded stable results that sometimes are used to reach opposite interpretations. But these puzzling differences reflect the two contrasting routes and goals in the search for consistency, not instabilities in the data nor a neglect of psychometric principles. Theory-guided predictions within particular empirical contexts are needed now to explore more deeply when and how either discriminative or more generalized patterns of coherence occur, and to illuminate their psychological bases with increasing precision.