Multidimensionality and hierarchical data structure are common in assessment data. These design features, if not accounted for, can threaten the validity of the results and inferences generated from factor analysis, a method frequently employed to assess test dimensionality. In this article, we describe and demonstrate the application of the…

Item response tree (IRTree) models are a flexible framework to control self-reported trait measurements for response styles. To this end, IRTree models decompose the responses to rating items into sub-decisions, which are assumed to be made on the basis of either the trait being measured or a response style, whereby the effects of such person…

The purpose of this study is to compare alternative multidimensional scaling (MDS) methods for constraining the stimuli on the circumference of a circle and on the surface of a sphere. Specifically, the existing MDS-T method for plotting the stimuli on the circumference of a circle is applied, and its extension is proposed for constraining the…

An essential feature of the linear logistic test model (LLTM) is that item difficulties are explained using item design properties. By taking advantage of this explanatory aspect of the LLTM, in a mixture extension of the LLTM, the meaning of latent classes is specified by how item properties affect item difficulties within each class. To improve…

Several sources of bias can plague research data and individual assessment. When cultural groups are considered, across or even within countries, it is essential that the constructs assessed and evaluated are as free as possible from any source of bias and specifically from bias caused due to culturally specific characteristics. Employing the…

Modeling multidimensional test data with a unidimensional model can result in serious statistical errors, such as bias in item parameter estimates. Many methods exist for assessing the dimensionality of a test. The current study focused on DIMTEST. Using simulated data, the effects of sample size splitting for use with the ATFIND procedure for…

Validity evidence based on test content is of essential importance in educational testing. One source for such evidence is an alignment study, which helps evaluate the congruence between tested objectives and those specified in the curriculum. However, the results of an alignment study do not always sufficiently capture the degree to which a test…

Akaike's information criterion is suggested as a tool for evaluating fit and dimensionality in metric multidimensional scaling that uses least squares methods of estimation. This criterion combines the least squares loss function with the number of estimated parameters. Numerical examples are presented. The results from analyses of both simulation…

In 2001, Elliot and McGregor proposed a 2 x 2 (mastery-performance x approach- avoidance) achievement goal frameworks and developed a questionnaire to measure four goals (mastery-approach, mastery-avoidance, performance-approach, and performance-avoidance goals). This study examines the dual meanings of items in 2 x 2 achievement goal…

Recent research suggests that competitive work environments may influence individual's attitudes, behaviors, stress, and performance. Unfortunately, adequate measures of competitive environments are lacking. This article traces the development of a new multidimensional competitive work environment scale. An initial 59-item pool covering five…

As item response models gain increased popularity in large-scale educational and measurement testing situations, many studies have been conducted on the development and applications of unidimensional and multidimensional models. Recently, attention has been paid to IRT-based models with an overall ability dimension underlying several ability…

The effects of nonnormally distributed perceived distance between pairs of objects on the accuracy of recovered configurations of traditional multidimensional scaling were studied via simulation methods. Multidimensional scaling is shown to be robust with respect to violations of the assumption of normality. (Author/JKS)

Interscal is a program for subject-computer interactive multidimensional scaling. The program analyzes subsets of judgments of similarity as they are given and picks out dimension-defining stimuli; this capability allows for a great reduction in the number of judgments. Program features and options are described. (Author)

Intransitives in observers' preference judgements for multidimensional natural landscape scenes are examined. Thurstone's Law of Comparative Judgement (LCJ) psychophysical scaling routine is used to scale landscape preference. Both the method of Rank Ordering (RO) and the method of Paired Comparisons (PC) are used to gather the raw data necessary…

TMFA, a FORTRAN program for three-mode factor analysis and individual-differences multidimensional scaling, is described. Program features include a variety of input options, extensive preprocessing of input data, and several alternative methods of analysis. (Author)