A FORTRAN program for clustering variables using the alpha coefficient of reliability is described. For batch operation, a rule for stopping the agglomerative precedure is available. The conversational version of the program allows the user to intervene in the process in order to test the final solution for sensitivity to changes. (Author/JKS)

This program computes specific category agreement levels for both nominally and ordinally scaled data. For ordinally scaled data, an option is available for collapsing the original scale to a smaller number of categories, with the goal of improving the level of interrater reliability for the rating scale. (Author)

Designed to measure self-actualization as defined by Abraham Maslow, the Jones Self Actualizing Scale, as assessed in this study, possesses content validity, reliability, and a number of other positive characteristics. (JC)

When raters in a reliability study are a random sample, inferences about the intraclass correlation coefficient must be based on three mean squares from the analysis of variance: between subjects, between raters, and error. An approximate confidence interval for the parameter is presented as a function of these mean squares. (Author/JKS)

The relationships among Rao's canonical factor analysis, Kaiser and Coffrey's alpha factor analysis, and Cronbach's alpha coefficient are discussed. Implications for test reliability and validity are noted. (JKS)

Suggests four questions teachers can ask to determine whether a standardized test has provided accurate information about a particular student. (DD)

Confusion in the literature between the concepts of internal consistency and homogeneity has led to a misuse of coefficient alpha as an index of item homogeneity. This misuse is discussed and several indices of item homogeneity derived from the model of common factor analysis are offered as alternatives. (Author/JKS)

Results from comparative testing indicate that fingertip blood is a valid indicator of antecubital venous hematocrit (hct) and hemoglobin (hgb), and that hct ratios determined on the Coulter counter are comparable to those found by the microhematocrit method. (MB)

A method of estimating item characteristic functions is proposed, in which a set of test items, whose operating characteristics are known and which give a constant test information function for a wide range of ability, are used. The method is based on maximum likelihood estimation procedures. (Author/JKS)

Measurement error in dependent variables reduces the power of statistical tests to detect mean differences of specified magnitude. Procedures for determining power and sample size that consider the reliability of the dependent variable are discussed and illustrated. Methods for estimating reliability coefficients used in these procedures are…

Twelve children with Down's syndrome (ages 3-5 years) were tested six times over 2.5 months on three Piagetian infant search tasks. Results suggested that cognitive ability of this population may be poorly measured by single-session testing and that caution is necessary when using tests designed for and validated on younger, nonretarded subjects.…

Two new methods for constructing a credibility interval (CI)--an interval containing a specified proportion of true validity description--are discussed, from a frequentist perspective. Tolerance intervals, unlike the current method of constructing the CI, have performance characteristics across repeated applications and may be useful in validity…

This article discusses the ethical implications of using tests intended only to protect the blood supply as diagnostic or prognostic tests for Acquired Immune Deficiency Syndrome (AIDS). The reliability of these tests and the confidentiality of their results are discussed, along with ethical issues of research regarding AIDS. (MT)

Evaluated a short form of the Roommate Rapport Scale that would maintain the scale's reliability and eliminate potentially objectionable items using students (N=320) who resided in dormitories. Results showed the short form to be reliable and unidimensional. (ABL)

Self-, peer, and supervisor ratings were obtained for simulated interviews using seven different measures of counseling performance. Results indicated significant differences among self, peer, and supervisor ratings and among four of the seven dependent measures. (Author/BL)