Errors in the quantification of uncertainty: A product of heuristics or minimal probability knowledge base?

The use of intuitive heuristics (e. g. representativeness and availability) has been put forward as an explanation for peoples' assignment of probabilities (Tversky and Kahneman, 1971). This phenomenon is seen as robust since experts as defined by education (professional psychologisis), despite advanced training in statistics and methodology, rely on the same heuristics as novices (lay people). Both experts and novices, as defined by education, were studied in a series of experiments and further classified as experts and novices according to their probability knowledge base, prior to receiving (or not) a brief (15-minute) training session. Immediately following training, subjects completed a probability test which consisted of ten Tversky and Kahneman (e. g. 1974) problems. The training significantly increased the number of problems correctly solved on the probability test and eliminated the expert/novice education classification. The results of a follow-up test 5 weeks after the experiment indicated that the training group maintained its superior performance. It is proposed that failure to use proper methods of probability assignment may not be due to intrinsic human inference biases or heuristics, but is a result of a minimal probability knowledge base.     

Automation of learning-set testing: The video-task paradigm

Researchers interested in studying discrimination learning in primates have typically utilized variations in the Wisconsin General Test Apparatus (WGTA). In the present experiment, a new testing apparatus for the study of primate learning is proposed. In the video-task paradigm, rhesus monkeys (Macaca mulatta) respond to computer-generated stimuli by manipulating a joystick. Using this apparatus, discrimination learning-set data for 2 monkeys were obtained. Performance on Trial 2 exceeded 80% within 200 discrimination learning problems. These data illustrate the utility of the video-task paradigm in comparative research. Additionally, the efficient learning and rich data that were characteristic of this study suggest several advantages of the present testing paradigm over traditional WGTA testing.     

A program for constructing SVT tests: An alternative way of assessing text comprehension

The sentence verification technique (SVT), developed by Royer, Hastings, and Hook (1979), provides developmental and educational researchers with an alternative way of assessing text comprehension based on all of the information contained in a passage. Students must decide if test sentences have the same meaning as sentences that appeared in an original passage. The program described here automates the more laborious aspects of constructing SVT tests. The user must create a passage using a word processor. The program will prompt the user for information as needed. Finally, printable text files (SVT test and answer key) are generated. The program is written in BASIC for IBM and IBM-compatible computers.     

Abuse of persons with mental retardation: A literature review

The literature reports a number of reasons why abuse of people with mental retardation occurs. These causes of abusive behavior can be divided into three categories: organizational variables, staff characteristics, and client characteristics. The author examines each of the variables and presents recommendations for reducing their contributions to abusive behavior.     

A controlled comparative investigation of psychological treatments for chronic sleep-onset insomnia

A sample of physician-referred chronic insomniacs was randomly allocated to either progressive relaxation, stimulus control, paradoxical intention, placebo or no treatment conditions. Treatment process and outcome were investigated in terms of mean and standard deviation (night to night variability) measures of sleep pattern and sleep quality. Only active treatments were associated with significant improvement, but the nature of treatment gains varied. In particular, stimulus control improved sleep pattern, whereas relaxation affected perception of sleep quality. All improvements were maintained at 17 month follow-up. Results are discussed with reference to previous research and guidelines are given for clinical practice.     

Adolescent suicide attempters presenting to a pediatric facility

This study profiles the characteristics of adolescent suicide attempters and the treatment they received in a pediatric emergency room (ER). A retrospective chart review of 4,072 adolescents seen in the ER at a children's hospital (CH) from July 1984 to June 1985 was undertaken. Twenty-seven adolescents who had deliberately injured themselves were identified. The average age was 14 years 7 months (range 11-19 years). Fifty-two percent of the patients were white and 78% were female. Ingestion was the most common method (78%), followed by attempted hanging (11%), and wrist laceration (7%). After evaluation by a pediatrician in the ER, 30% of the patients were treated and released, 11% were transferred directly to a psychiatric hospital, and 59% were admitted to the CH, with an average hospital stay of 1.88 days. Once hospitalized, consultations from psychiatry (81%), social service (50%), psychology (19%), and neurology (6%) were obtained. At the time of discharge from either the ER or CH, the patients had a variety of plans for ongoing care, with 52% being referred to outpatient counseling, 37% being transferred to a psychiatric hospital, and 11% having no documented plan for ongoing care. These results demonstrate that the evaluation of suicidal adolescents cared for in a pediatric facility may be episodic and suggest the need for a comprehensive program to approach the problem.