Reviews research on juror, witness, and courtroom factors that influence a child's credibility on the witness stand. Presents results of studies of juror reactions to child witnesses. Observes that the influence of children's testimony may be great, but also that corroborating evidence may significantly determine the influence of children's…

A principal components analysis of matrices of Spearman's rho statistic for inter-rater reliability is proposed as an alternative to Kendall's coefficient of concordance. Advantages and possible uses of the proposed method are presented. (JKS)

Reliability is one of the chief characteristics researchers consider when judging the quality of data used in their studies. Within the positivist paradigm, data are typically quantified, and thus it is relatively easy to derive estimates of reliability. Within the interpretivist paradigm, however, the idea of data reliability is a looser science.…

Much of the current research concerning reliability emphatically suggests that researchers should gather their own reliability estimates when administering an instrument. It has also been recommended that data with low reliability be discarded. While some data obtained from instruments that originally yielded reliable results may be unreliable, it…

Proposes a test for change in composite reliability as a result of scale revision or modification. The test, which is useful for examining whether a revision changes the population reliability of a scale undergoing development, is illustrated with two examples. (SLD)

Developed a general framework to estimate total test or testlet reliability with either fixed or random factors that is based on hierarchical factor analysis. Illustrates the framework with an example based on real data. (SLD)

Studied the sample coefficient alpha for each of the five subscales of the Hopkins Symptom Checklist (HSL; L. Derogaitis and others, 1974) in a sample of 419 adults. Findings show that the normal-theory-based distribution has a systematic bias in describing the behavior of the sample coefficient alpha. (SLD)

Illustrates that there is a critical distinction between reliability and accuracy, explaining through a hypothetical example of shoe fitting that high test reliability does not guarantee good accuracy without consideration of percentile rank scoring, complex measurement models, and other technical detail. (SLD)

It is recognized that the typical difference score used by educators is likely to be relatively weak in reliability. Formulas are developed for estimating changes in the reliability of X-Y under the assumption of equal or unequal variances before and after reliabilities are modified. (SLD)

Explains the use of Strahan's Consistency Index to manage the occurrence of ties in Holland's occupational type codes. (SK)

Developed a statistical test for the hypothesis of the equality of extrapolated coefficients when the original values (Cronbach's alpha) are based on the same sample of persons and, therefore, are statistically dependent. Monte Carlo studies show that the test precisely controlled Type I error, even with small numbers of parttest units or raters.…

This article provides a meta-analysis of 38 studies of J. E. Helms and R. T. Carter's (1990) White Racial Identity Attitude Scale. Systematic measurement errors are implicated as influences on the measure's reliability and validity. (Author/MKA)

Contrary to common belief, reliability estimates of number-right multiple-choice tests are not inflated by speededness. Because examinees guess on questions when they run out of time, the responses to these questions generally show less consistency with the responses of other questions, and the reliability of the test will be decreased. The…