It is generally believed that the correction formula will yield exact correlational values only when the regression of z on x is both linear and homoscedastic. The formula is shown to hold for nonlinear heteroscedastic relationships. A simple sufficient condition for formula validity and estimation predictions is demonstrated in a numerical…

A simple, usefully accurate approximation of the standard error of measurement is proposed for use by classroom teachers. An empirical comparison with Lord's approximation indicated that, though not as easy to calculate as Lord's, this approximation is more practical because it is useful at any point in the score distribution. (BW)

For tests used to make pass/fail decisions, the relevant standard error of measurement (SEM) is the SEM at the passing score. If the test is highly stratified, this SEM should be estimated by a split-halves approach. A formula and its derivation are provided. (Author)

The normalized mean is developed and discussed as a descriptive measure of central location. The advantages of the normalized mean over the arithmetic mean, median, and trimmed mean are discussed. (Author)

Although Model A, the only norm-referenced evaluation procedure in the Title I Evaluation and Reporting System, requires no data other than the test scores themselves, it introduces two sources of bias and involved three test administrations. Roberts' two-test procedure offers the advantages of less bias and less testing. (RL)

Cohen's (TM 504 890) formal rules of intuitive probability lack normative or descriptive appeal, and his interpretation of the author's findings is not compelling. (CP)

In mastery testing, the raw agreement index and the kappa index may be estimated via one test administration when the test scores follow beta-binomial distributions. This paper reports formulae, tables, and a computer program which facilitate the computation of the standard errors of the estimates. (Author/CTM)

It has long been popular to utilize the least squares estimation procedure for fitting the multiple linear regression model to observed data. In this paper, two useful alternatives to least squares estimation in exploratory data analysis are examined: least absolute value estimation and Chebychev estimation. (Author/JKS)

The problem of objectively comparing two independently determined partitions of N objects or variables is discussed. A similarity measure based on the simple matching coefficient is defined and related to previously suggested measures. (Author/JKS)

Considers the application of game theory to library networks in two areas: the development of a systematic way to study individual coalitions, and the stability of the network. (FM)

Describes physics formulas which can be used by law enforcement officials to determine the possible velocity of vehicles involved in traffic accidents. These include, among others, the slide to stop-level road, slide to stop-sloping roadway, and slide to stop-two different surfaces formulas. (JN)

Formulas are derived for computing the chi-square statistic from proportions or percentages, both for tests of goodness of fit and association. Advantages of the new formulas are given, as are some examples. (Author/MH)