A statistical method is described and illustrated which provides confidence envelopes around item response functions. Examples of 95 percent confidence envelopes for the one-, two-, and three-parameter logistic response models are given. In addition, the authors describe N-line plots, which show the genesis of the envelope as well as the density…

An approximation formula for the standard error of measurement was recently proposed by Garvin. The properties of this approximation to the standard error of measurement are described in this paper and illustrated with hypothetical data. It is concluded that the approximation is a systematic overestimate of the standard error of measurement…

Estimation of ability and item parameters in latent trait models is discussed. When both ability and item parameters are considered fixed but unknown, the method of maximum likelihood for the logistic or probit models is well known. Discussed are techniques for estimating ability and item parameters when the ability parameters or item parameters…

The purpose of this study was to evaluate the parallel processing impact of multiple-instruction multiple-data path (MIMD) computers on flight simulation software. Basic mathematical functions and arithmetic expressions from typical flight simulation software were selected and run on an MIMD computer to evaluate the improvement in execution time…

Comparisons are made between the errors obtained when approximating the integral with the midpoint rule, the trapezoidal rule, and Simpson's rule. (MP)

This study compared two approximations for normalizing noncentral F distributions: one based on the square root of the chi-square distribution (SRA), the other derived from a cube root of the chi-square distribution (CRA). The CRA was superior, and generally provided an excellent approximation for noncentral F. (Author/BW)

This paper reviews the distinctions between classical and partial eta square and derives a formula for use in those complex analysis of variance designs in which the investigator desires a measure of classical eta square and has access only to the F-tests and relevant degrees of freedom. (Author/BW)

The purpose of this study was to investigate the degree to which various selected test item discrimination indices reflect a common factor. The indices used include the point-biserial, biserial, phi and tetrachoric coefficients, Flanagan's approximation of the product-moment correlation, Gulliksen's item reliability index, and Findley's difference…

Eight asymptotically robust tests of population correlation coefficient equality are proposed and are studied along with two parametric tests. Monte Carlo simulation is used to compare the small sample performance of these ten procedures. The sampled distributions consist of the normal distribution, two mixed normal distributions and four…

The annual Gallup "Attitudes to Education" Poll provides a good example of a situation in which a composite education system indicator can be developed. The Laspeyres formula is recommended for this purpose, as well as for analyzing and reporting a number of educational research results in general. (RL)

Some procedures for estimating internal consistency reliability may be superior mathematically to the more commonly used methods such as Coefficient Alpha. One problem is computational difficulty; the other is the possibility of overestimation due to capitalization on chance. (Author/CTM)