Describes a simplified method for converting raw scores to standard scores and transforming them to "T-scores" for easy comparison of performance. Obtaining letter grades from T-scores is discussed. A reading list is included. (GH)

The National Assessment of Educational Progress in-school sampling design is a three-stage stratified design. Stratification variables include region, size of community and socioeconomic status. The three levels of sample selection are Primary Sampling Units (PSUs), schools and students. In general, two and sometimes three PSUs are selected from…

Comparisons of corresponding values of phi and kappa coefficients were made for 270 instances of data generated by a Monte Carlo technique to simulate a test-retest situation. Data were generated for distributions with the same mean but three different levels of standard deviation, standard error of measurement and cutting score. Ten samples of…

One aim of criterion-referenced testing is to classify an examinee without reference to a norm group; therefore, any statements about the dependability of such classification ought to be group-independent also. A population-independent index is proposed in terms of the probability of incorrect classification near the cutoff true score. The…

Because it is difficult to ascertain the dimensionality of a test composed of binary items through the use of factor analysis alone, a method is proposed that combines item characteristic curve (ICC) theory with factor analysis. Factor structure of tetrachoric correlations is distorted by non-normal distribution of ability. Item characteristics…

The mathematical derivation of the statistics used for inference in some linear models assumes that the values of the independent variables are measured without error. This assumption is often disregarded when these models are utilized in research. This study is an investigation of the consequences of the violation of this assumption for one…

Besides the ubiquitous Pearson product-moment r, there are a number of other measures of relationship that are attenuated by errors of measurement and for which the relationship between true measures can be estimated. Among these are the correlation ratio (eta squared), Kelley's unbiased correlation ratio (epsilon squared), Hays' omega squared,…

The Werts-Linn procedure for dealing with categorical errors of measurement in "Comments on Boyle's 'Path Analysis and Ordinal Data'" in The American Journal of Sociology, volume 76, number 6, May 1971, is shown to be inappropriate to the problem of ordered categories. (For related document, see TM 002 301.) (DB)

Statistics are an essential tool for making proper judgement decisions. It is concerned with probability distribution models, testing of hypotheses, significance tests and other means of determining the correctness of deductions and the most likely outcome of decisions. Measures of central tendency include the mean, median and mode. A second…

This article describes a new testing method which can be used to screen learning-deficient children fast, reliably, and inexpensively out of any population of public school systems. (Editor)

The Wechsler Intelligence Scale for Children, and the revised form of that measure, were administered to a sample of sixth grade pupils. Although the correlation between measures was high, scores on the revised form were significantly lower. (JKS)

Statements made in a previous article of this journal concerning the Rasch latent trait test model are questioned. Methods of estimation, necessary sample sizes, several formuli, and the general usefulness of the Rasch model are discussed. (JKS)

Using the assumption of randomly parallel tests and concepts from generalizability theory, three signal/noise ratios for domain-referenced tests are developed, discussed, and compared. The three ratios have the same noise but different signals depending upon the kind of decision to be made as a result of measurement. (Author/JKS)

This paper analyzes ways in which the methods used to measure psychological constructs contribute invalidity to measurements. The analysis distinguishes between inadequacies stemming from the behaviors selected for measurement and the harmful effects generated by the measurement operations themselves. (BS)

Answer keys for physician and teacher licensing examinations were studied. The impact of variability on total errors of measurement was examined for answer keys constructed using the aggregate method. Results indicated that, in some cases, scorers contributed to a sizable reduction in measurement error. (Author/GDC)