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…

After a test is developed, most content validation analyses shift from ascertaining domain definition to studying domain representation and relevance because the domain is assumed to be set once a test exists. We present an approach that allows for the examination of alternative domain structures based on extant test items. In our example based on…

Spearman's factor-analytic model has been proposed as a unidimensional linear item response theory (IRT) model for continuous item responses. This article first proposes a reexpression of the model that leads to a form similar to that of standard IRT models for binary responses and discusses the item indices of difficulty discrimination and…

The purpose of this paper is to examine the capabilities of various procedures for sorting dichotomously-scored items into unidimensional subjects. The procedures include: factor analysis, nonmetric multidimensional scaling, cluster analysis, and latent trait analysis. Both simulated and real data sets of known structure were used to evaluate the…

Cliff's Index "c" derived from an item dominance matrix is utilized in a clustering approach, termed extracting Reliable Guttman Orders (ERGO), to isolate Guttman-type item hierarchies. A comparison of factor analysis to the ERGO is made on social distance data involving multiple ethnic groups. (Author/BW)

Academic psychology has long been composed of two disciplines, one experimental and one correlational. These two disciplines each developed their own method of studying structure in data: multidimensional scaling (MDS) and factor analysis. Both methods use similar kinds of input data, proximity measures on object pairs. Both represent the object…

Little is known about environmental concerns and attitudes among people in former Soviet bloc countries in Eastern Europe despite widespread perceptions of severe environmental problems. The authors addressed this gap by examining Bulgarians' environmental concerns with a focus on whether the new environmental paradigm (NEP) scale can reliably…

Order Analysis is a multidimensional scaling (MDS) technique for determining order among items. This paper reviews articles by different authors describing various components of ordering theory. A common nomenclature is constructed to link together the various ideas and is applied to a fairly simple set of data. Topics discussed include a more…

Many multidimensional item response theory (IRT) models have been proposed. A comparison is made between the so-called full information models and the models that use only pairwise information. Three multidimensional models described are: (1) the compensatory model of R. D. Bock and M. Aitken (1981) using the computer program TESTFACT; (2) a model…

One of the major assumptions of latent trait theory is that the items in a test measure a single dimension. This report describes an investigation of procedures for forming a set of items that meet this assumption. Factor analysis, nonmetric multidimensional scaling, cluster analysis and latent trait analysis were applied to simulated and real…

In order to determine the effectiveness of multidimensional scaling (MDS) in recovering the dimensionality of a set of dichotomously-scored items, data were simulated in one, two, and three dimensions for a variety of correlations with the underlying latent trait. Similarity matrices were constructed from these data using three margin-sensitive…

Geometric approaches to representing interrelations among tests and items are compared with an additive tree model (ATM), using 2,644 examinees and 2 other data sets. The ATM's close fit to the data and its coherence of presentation indicate that it is the best means of representing tests and items. (TJH)

A multidimensional item response theory (IRT) model for polytomously scored items, based on the graded response model and using the normal ogive, is developed; and an EM algorithm that may be used to estimate the parameters of the model is also discussed. The model is illustrated through a simulation study in which the polytomous item responses of…

A procedure for interpreting multiple-discrimination indices from a multidimensional item-response theory analysis is described and demonstrated with responses of 1,635 high school students to a multiple-choice test. The procedure consists of converting discrimination parameter estimates to direction cosines and analyzing the angular distances…

The sources of multidimensionality found in several different forms of a licensure examination were studied. The relationship between one source of multidimensionality, differential item functioning (DIF) (or factors producing DIF), and content characteristics was explored in an attempt to isolate aspects of training or curriculum that could…