Quantiles for finite mixtures of normal distributions are computed. The difference between a linear combination of independent normal random variables and a linear combination of independent normal densities is emphasized. (Contains 3 tables and 1 figure.)

A survey of psychology graduate admissions committee chairs revealed 5 categories of mistakes applicants make that diminish their probability of acceptance. We discuss 3 strategies that psychology departments can use to decrease the likelihood that students will commit these mistakes in their graduate school applications and provide suggestions…

Consider the nonparametric regression model Y = m(X)+ [tau](X)[epsilon], where X and [epsilon] are independent random variables, [epsilon] has a median of zero and variance [sigma][squared], [tau] is some unknown function used to model heteroscedasticity, and m(X) is an unknown function reflecting some conditional measure of location associated…

Statistical terms are accurate and powerful but can sometimes lead to misleading impressions among beginning students. Discrepancies between the popular and statistical meanings of "conditional" are discussed, and suggestions are made for the use of different vocabulary when teaching beginners in applied introductory courses.

Four experiments tested context switch effects on acquisition and extinction in human predictive learning. A context switch impaired probability judgments about a cue-outcome relationship when the cue was trained in a context in which a different cue underwent extinction. The context switch also impaired judgments about a cue trained in a context…

Some probabilistic illustrations of the reliability coefficient are provided to assist in interpretation of this measure. All explanations are derived under the assumption that the joint distribution of examinee scores from two parallel tests is well approximated by a bivariate normal distribution.

There are test-equating situations in which it may be appropriate to fit a loglinear or other type of probability model to the joint distribution of a total score on a test and a score on part of that test. For anchor test designs, this situation arises for internal anchor tests, which are embedded within the total test. Similarly, a part-whole…

Examples are given which show how Karnaugh maps can be used in questions involving probability. (DT)

The principal objects of the investigation reported were, first, to study qualitative probability relations on Boolean algebras, and secondly, to describe applications in the theories of probability logic, information, automata, and probabilistic measurement. The main contribution of this work is stated in 10 definitions and 20 theorems. The basic…

Two designs for comparing a judge's ratings with a known standard are compared: (1) Subjects are categorized into classes, with no knowledge of the size of either group; and (2) the judge is told the actual number allowed in each class. The probability distribution of the total number of correct choices is developed for each case, and their power…

A computer program for testing the association of two nominal variables using Fisher's exact probability test is described. Theoretical corrections according to recent literature are made. Various methods of discovering the source of association at the cellwise level are given. (Author/JKS)

A class of estimators which are asymptotically unbiased and mean square consistent are exhibited. Theorems giving necessary and sufficient conditions for uniform asymptotic unbiasedness and for mean square consistency are presented along with applications of the estimator to certain statistical problems. (Author/RC)

Analyzes the Gambler's Fallacy, the perception of interdependence among events which are in fact unrelated. Describes how reasoning errors occur when the perceived interdependence influences predictions about subsequent events. Elaborates the distinction between Gambler's Fallacy and similar but sound reasoning strategies. (BH)

It is suggested that theorists may develop both independence and exclusivity forms of multiple-process models, allowing choice between them to be made on empirical rather than a priori grounds. This theoretical approach is adopted in the specific case of memory retrival (Author/LMO)