In 1881, Donald MacAlister posed a problem in the "Educational Times" that remains relevant today. The problem centers on the statistical evidence for the effectiveness of a treatment based on a comparison between two proportions. A brief historical sketch is followed by a discussion of two default Bayesian solutions, one based on a…

To date, small sample problems with latent growth models (LGMs) have not received the amount of attention in the literature as related mixed-effect models (MEMs). Although many models can be interchangeably framed as a LGM or a MEM, LGMs uniquely provide criteria to assess global data-model fit. However, previous studies have demonstrated poor…

The use of causal indicators to formatively measure latent constructs appears to be on the rise, despite what appears to be a troubling lack of consistency in their application. Scholars in any discipline are responsible not only for advancing theoretical knowledge in their domain of study but also for addressing methodological issues that…

A concise method for computing areas under the normal curve using only functions typically found on desk and hand calculators is given. One version of this method will give three-decimal-pace accuracy, and a second, simpler version gives accuracy to two places. (Author/JKS)

A table of critical values is presented for use with Chacko's ordered alternatives test for the analysis of variance. (Author/JKS)

Two computer programs (one batch, one interactive) are designed to provide statistics for a weighted linear combination of several component variables. Both programs provide mean, variance, standard deviation, and a validity coefficient. (Author/JKS)

An algorithm for updating the means of variances of a norm group after each computer-assisted administration of a test is described. The algorithm does not require storage of the whole data set, and provides for unlimited, continuous expansion of the test norms. (Author)

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…

META-RAND, a Statistical Analysis System macro that generates random values used for calculating correlations in a meta analysis, is described. Output consists of uncorrected and corrected mean and variances of "r" and several measures of the degree of homogeneity or heterogeneity in the data. (SLD)

Formulae and graphs are presented allowing computation of the variances of three prototypical distributions over a finite number of categories. The uses of the variances of the maximum variance distribution, the uniform distribution and a unimodal triangular distribution to make inferences about distribution shapes are shown in several examples.…

Several advantages to the use of different kinds of factor scores as independent variables in a multiple regression equation are reported. A computer program is presented which will calculate a regression equation using a variety of factor scores. (Author/JKS)

The General Education Performance Index (GEPI) is a comparatively short test covering the same content as the General Educational Development Test (GED), which takes ten hours to administer. Correlations of the subtests of the GEPI with the GED ranged from .28 to .57. (JKS)

An Angoff method and a frequency estimation equipercentile equating method were compared, using data from three forms of a 200-item multiple-choice certification test. Data requirements are fewer and computational requirements less burdensome for the former than for the latter method. However, results of the two methods are not interchangeable.…