This article reports on a subset of results from a larger study which examined middle and high school students' probabilistic reasoning. Students in grades 5, 7, 9, and 11 at a boys' school (n = 173) completed a Probability Inventory, which required students to answer and justify their responses to ten items. Supplemental clinical interviews…

In the standard Iowa Gambling Task (IGT), participants have to choose repeatedly from four options. Each option is characterized by a constant gain, and by the frequency and amount of a probabilistic loss. Crone and van der Molen (2004) reported that school-aged children and even adolescents show marked deficits in IGT performance. In this study,…

This study aimed to determine the probability that a child with cerebral palsy (CP) will lose or gain ambulatory ability through adolescence and young adulthood. We analyzed retrospectively data from 1987 to 2002 on Californians with CP initially aged 10 years (SD 0.9y; n=7550 [4304 males, 3246 females]) and 25 years (SD 0.8y; n=5721 [3261 males,…

This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

Mixture modeling is a widely applied data analysis technique used to identify unobserved heterogeneity in a population. Despite mixture models' usefulness in practice, one unresolved issue in the application of mixture models is that there is not one commonly accepted statistical indicator for deciding on the number of classes in a study…

Consistent condom use, particularly by promiscuous individuals, is a major safeguard against sexually transmitted diseases, including HIV/AIDS. This study examines some demographic factors that may affect such use among Bangladeshi female commercial sex workers at a brothel in Tangail (n = 196; mean age = 23.44 years), and the streets of Dhaka (n…

Probability is an essential tool for understanding heredity and modern genetics, yet many students have difficulty with this topic due to the abstract and quantitative nature of the subject. To facilitate student learning of probability in genetics, we have developed a set of hands-on, cooperative activities that allow students to determine…

This study presents the results of a partial credit Rasch analysis of in-depth interview data exploring statistical understanding of 73 school students in 6 contextual settings. The use of Rasch analysis allowed the exploration of a single underlying variable across contexts, which included probability sampling, representation of temperature…

Four different approaches to residual entropy (the entropy remaining in crystals comprised of nonsymmetric molecules like CO, N[subscript 2]O, FClO[subscript 3], and H[subscript 2]O as temperatures approach 0 K) are analyzed and a new method of its calculation is developed based on application of the Boltzmann distribution. The inherent connection…

To examine the effect of reinforcer density in prize-based abstinence reinforcement, heroin/cocaine users (N = 116) in methadone maintenance (100 mg/day) were randomly assigned to a noncontingent control group (NonC) or to 1 of 3 groups that earned prize draws for abstinence: manual drawing with standard prize density (MS) or computerized drawing…

The failure of Hume's "constant conjunction" to describe apparently causal relations in science and everyday life has led to various "probabilistic" theories of causation of which the study by P. C. Suppes (1970) is an important example. A formal model that was developed for the analysis of comparative agricultural experiments…

Report describes the rationale underlying a procedure for eliciting personal estimates of probabilities utilizing a proper scoring rule, and illustrates some new techniques for calibrating those probabilities and providing better feedback to students learning to assess uncertainty. (Author)

THIS BIBLIOGRAPHY SUPPLEMENT LISTS MATERIALS ON VARIOUS ASPECTS OF ACHIEVEMENT. APPROXIMATELY 60 REFERENCES ARE PROVIDED TO DOCUMENTS DATING FROM 1961 TO 1966. JOURNALS, BOOKS, AND REPORT MATERIALS ARE LISTED. SUBJECT AREAS INCLUDED ARE ACHIEVEMENT LEVEL, ACADEMIC ACHIEVEMENT, ACHIEVEMENT MOTIVATION, UNDERACHIEVERS, PROBABILITY ESTIMATES, AND…

The defining property of an admissible scoring system is that any individual perceives himself as maximizing his expected score by reporting his true subjective distribution. The use of admissible scoring systems as a measure of probabilistic forecasts is becoming increasingly well-known in those cases where the forecast is a discrete distribution…