This study develops a theoretical model for the costs of an exam as a function of its duration. Two kind of costs are distinguished: (1) the costs of measurement errors and (2) the costs of the measurement. Both costs are expressed in time of the student. Based on a classical test theory model, enriched with assumptions on the context, the costs…

A new test index is defined as the probability of obtaining two randomly selected test scores (PDTS) as statistically different. After giving a concept definition of the test index, two simulation studies are presented. The first analyzes the influence of the distribution of test scores, test reliability, and sample size on PDTS within classical…

The classical estimate of a binomial probability function is to estimate its mean in the usual manner and to substitute the results in the appropriate expression. Two alternative estimation procedures are described and examined. Emphasis is given to the single administration estimate of the mastery test reliability. (Author/CTM)

Although a great deal of attention has been devoted over a period of years to the estimation of reliability from item statistics, there are still gaps in the mathematical derivation of the Kuder-Richardson results. The main purpose of this paper is to fill some of these gaps, using language consistent with modern probability theory. (Author)

Power analysis is in essence a technique for estimating the probability of obtaining a specific minimum observed effect size. Power analysis techniques are applied to research planning problems in test reliability studies. A table for use in research planning and hypothesis testing is presented. (Author)

Using the concepts of conditional probability, conditional expectation, and conditional independence, the main results of the classical test theory model can be derived in a very few steps with minimal assumptions. The present effort explores the possibility that present classical test theories can be further condensed. (Author/RC)

A computer program simulated guessing on multiple-choice test items and calculated deviation IQ's from observed scores which contained a guessing component. Extensive variability in deviation IQ's due entirely to chance was found. (Author/LMO)

Bilevel dimensionality of probability was examined via factor analysis, Rasch latent trait analysis, and classical item analysis. Results suggest that when nonstandardized measures are the criteria for achievement, relying solely on estimates of content validity may lead to erroneous interpretation of test score data. (JKS)

The Guttman scale is discussed from the viewpoint of errors in response patterns. The errors are assumed to be distributed as a binomial. A double-barreled significance test is suggested having two probabilities: high probability and low probability. (Author)

Three numerical coefficients for analyzing the validity and reliability of ratings are described. Each coefficient is computed as the ratio of an obtained to a maximum sum of differences in ratings. The coefficients are also applicable to the item analysis, agreement analysis, and cluster or factor analysis of rating-scale data. (Author/BW)

Procedures for computing content validity and consistency reliability coefficients and determining the statistical significance of these coefficients are described. Procedures employing the multinomial probability distribution for small samples and normal curve probability estimates for large samples, can be used where judgments are made on…