Rigorous comparison of the reliability coefficients of several tests or measurement procedures requires a sampling theory for the coefficients. This paper summarizes the important aspects of the sampling theory for Cronbach's (1951) coefficient alpha--a widely used internal consistency coefficient. This theory enables researchers to test a…

The NFER has devised a set of English proficiency tests suitable for immigrant junior-school children. What do these tests reveal about the levels of linguistic skill found in different immigrant groups? (Editor)

Use of Tukey's Jackknife in establishing a confidence interval around the population coefficient alpha is explored and the robustness of Feldt's procedure along with ten variants of the Jackknife when the data do not conform to the necessary normality requirements are evaluated. Only two of the variants compared to Feldt's approach. (RC)

The paper points out that, in working with special groups, correlations are often distorted because the variability of the measures being correlated are restricted in the groups. Presented is a formula whereby a Pearson product-moment correlation can be corrected for restrictions in range in situations where the basis of selection is unmeasured,…

This investigation had two major purposes. The first was to explore the use of an inferential technique called Tukey's Jackknife in establishing a confidence interval about cooefficient alpha reliability. The second purpose was to study the robustness of the Feldt and the jackknife procedures when the data fails to satisfy usual normality…

Three United States Air Force job inventory procedures were studied in depth, categorizing task statements by duties, interviewing technical advisers for job information, and detecting bias in survey samples. Variations in the usual grouping of supervisory tasks were found to be occasionally necessary. Depending upon the career ladder surveyed,…

While school systems most often use achievement test results for individual appraisals, increasing attention to program evaluation and accountability requires that test results be used for institutional appraisals as well. When institutional test results are desired--that is, results for schools or school districts--not all pupils need be tested.…

Some sampling characteristics of three estimators of the intraclass correlation were investigated under a variety of conditions within the context of a one-way analysis of variance. The results promote caution in the use of all three estimators. The three estimators differed very little in their bias or in their standard errors. (Author/JKS)

Five branch libraries measured the quantity of books, sound recordings, and periodicals in their catalogs in comparison with the number available for loan. A sampling method similar to those used for political pools and market research was employed. (JAB)

In negotiating to obtain a sample of records from a computer file, it is important to be able to present a simple program that will produce a representative and valid sample. This article describes two procedures: (1) an interval selection method; and (2) a random numbers file. (JAZ)

Information loss occurs when continuous data are grouped in discrete intervals. After calculating the squared correlation coefficients between continuous data and corresponding grouped data for four population distributions, the effects of population distribution, number of intervals, and interval width on information loss and recovery were…