In educational research, nonessential factors are commonly ignored and when accounted for, they are often treated statistically as fixed effects. Yet many researchers in these situations generalize their findings beyond the specific levels selected; however, the analyses may require treating the factor as a random effect. Such inappropriate…

The Bootstrap method, a computer-intensive statistical method of estimation, is illustrated using a simple and efficient Statistical Analysis System (SAS) routine. The utility of the method for generating unknown parameters, including standard errors for simple statistics, regression coefficients, discriminant function coefficients, and factor…

In research, data sets often occur in which the variance of the distribution of the dependent variable at given levels of the predictors is a function of the values of the predictors. In this situation, the use of weighted least-squares (WLS) or techniques is required. Weights suitable for use in a WLS regression analysis must be estimated. A…

The term "ipsative" refers to measurement based on intra-individual comparisons. The research literature in the social sciences contains many cautions about using ipsative data in multivariate analysis. The purpose of this paper is to identify the problems associated with the multivariate and regression analyses of ipsative data and to…

This paper provides empirical data on two approaches to statistically equate scores derived from the direct assessment of writing. These methods are linear equating and equating based on the general polychotomous form of the Rasch model. Data from the Maryland Functional Writing Test are used to equate scores obtained from two prompts given in…

The sources of variability in the Angoff standard-setting procedure, when applied to the Alabama High School Graduation Examination (AHSGE), were examined. The sources of variability examined are judges, rounds (replications), competencies (items), and interactions among these three sources. After training, the judges were given a statement of a…

Scores of two groups of White and Hispanic children at 11 age levels from 2.5 years to 12.5 years were assessed. The scores were drawn from the Kaufman Assessment Battery for Children (K-ABC), an individually administered assessment battery designed to measure intelligence and achievement and intended for minority group assessment. Reliability…

The purpose of this paper is to provide an overview of the analysis of data collected by the National Assessment of Educational Progress (NAEP). In simplest terms, the analysis can be characterized as establishing baseline estimates of the percentages of young Americans possessing certain skills, knowledge, understandings, and attitudes and…

Drawing from work on the meta-analysis of over 500 validation studies of the General Aptitude Test Battery (GATB) by the U.S. Employment Service, the paper presents a methodological message and a substantive message. Gene Glass's methods, as used by Edwin Ghiselli in personnel selection, ignore study artifacts (sampling error, error of…

Using data from a National Child Development Study (NCDS) in Great Britain, the applications of instrumental variable methods and structural equation models to estimating instrumental variables are presented. A subset of the longitudinal educational and home background data on children born in England, Wales and Scotland in a March week of 1958 is…

The Feldt-Gilmer congeneric reliability coefficients make it possible to estimate the reliability of a test composed of parts of unequal, unknown length. The approximate standard errors of the Feldt-Gilmer coefficients are derived via a method using the multivariate Taylor's expansion. Monte Carlo simulation is employed to corroborate the…

Two fundamental problems in mental test theory are to estimate true score and to estimate the amount of error when testing an examinee. In this report, three probability models which characterize a single test item in terms of a population of examinees are described. How these models may be modified to characterize a single examinee in terms of an…

Errors in oral reading tests result from inaccuracies that tend to creep in because children are not totally consistent while taking a test and from inaccuracies caused when the examiner does not catch a word recognition error, giving credit for an answer that is more wrong than right or vice versa. Every test contains a standard error of…

In all latent trait models there is an equation which describes the probabilistic outcome of the interaction of a person with a known ability and an item with a known difficulty. This modeled outcome can be compared to the observed outcome, and the residuals can be summed over the items to assess the fit of the person to the model. Various…

Stockton Unified School District's successful strategy of using a locally developed, non-normed achievement test to implement the norm referenced model of the Title I Evaluation and Reporting System (Model A2) is described. Documented are the procedures involved in the development of a curriculum guide and test items, and the administration of…