This paper presents a new technique in which covariates are controlled and evaluation data still are presented graphically in a manner that makes sense to policy makers. An illustration is provided using data drawn from an evaluation by the author of a major National Science Foundation (NSF) university funding program. (Author)

Discusses the problem of determining an adequate sample size for an information retrieval experiment comparing two systems on separate samples of requests. The application of statistical methods to information retrieval experiments is discussed, the Mann-Whitney U Test is used for determining minimum sample sizes, and variables and distributions…

Discusses the interdependencies between parameter estimation and properties of probabilistic models, such as dependency assumptions, binary vs. nonbinary features, and estimation sample selection. An optimum estimation for binary features applicable to information retrieval is defined, a method for computing this estimation using empirical data is…

Argues that a major difficulty in using Lotka's law in information science arises from the misuse of goodness of fit tests in parameter estimation. Three approaches for studying Lotka's law are presented: an index approach, a time series approach, and a generating mechanism incorporating these two influential variables to derive an equilibrium…

Power and Type I error rates were estimated for contingency tables with small sample sizes for the following four types of tests: (1) Pearson's chi-square; (2) chi-square with Yates's continuity correction; (3) the likelihood ratio test; and (4) Fisher's Exact Test. Various marginal distributions, sample sizes, and effect sizes were examined. (SLD)

The primary purpose of this study was to examine significant differences, if any, in student achievement in the area of math and science of students taught by traditionally certified teachers and alternatively certified teachers. This study examined alternatively certified teachers, as identified from through the Georgia TAPP (Teacher Alternative…

Validity generalization meta-analysis (VG) examines the extent to which the validity of an instrument can be transported across settings. VG offers correction and summarization procedures designed in part to remove the effects of statistical artifacts on estimates of association between criterion and predictor. By employing a random effects model,…

The effects of sample size, number of variables, and population value of the congruence coefficient on the sampling distribution of the congruence coefficient were examined. Sample data were generated on the basis of the common factor model, and principal axes factor analyses were performed. (Author/LMO)

Presents a new measure of retrieval evaluation called corrected precision, which refines the traditional measures of recall and precision by taking into account differences among users in their selectivity when judging document relevance. The formula for calculating corrected precision is explained, and results from an empirical study of relevance…

Examined the effects of type of distribution and type of response scale on observed integration patterns in five, six, and seven year olds. Findings showed that the effect of two factors, age and type of scale, were significant. (SH)

Determines the frequency distribution of Brainstem Auditory Evoked Potential variables (BAEP) for premature babies at different stages of development--normal newborns, infants, young children, and adults. The author concludes that the assumption of normality underlying most "standard" statistical analyses can be met for many BAEP…

Tables for testing clinical hypotheses about counseling clients are presented, and their use is described. Primary uses are determining a critical value or cutoff score on a predictor that can be used to classify an individual as a member of a clinical group, and instructing those unfamiliar with the limitations of tests about the conditions under…

Describes the development and testing of the Bath County Computer Attitudes Scale (BCCAS), which is designed to measure elementary and secondary school students' attitudes toward computers. Preliminary and revised versions are reviewed, and a analysis of data supports the validity of the BCCAS as a measure of computer attitudes. (Author/LRW)

In this article, the author documents the learning disadvantage of rural primary school students in sub-Saharan Africa and attempts to identify the factors underlying such disadvantages. Analyzing data from 14 school systems participating in the second study of the Southern and Western Africa Consortium for Monitoring Educational Quality (SACMEQ…

Any voucher program that is going to have a major impact on a public education system is likely to require an expansion of private schools in order to accommodate increased demand; however, little is known about where private schools open and therefore how a major voucher program might affect private school availability in various communities.…