The Likert rating scale procedure is often used in conjunction with a graded disagree-agree response scale to measure attitudes. Item characteristic curves associated with graded disagree-agree responses are generally single-peaked, nonmonotonic functions of true attitude. These characteristics are, thus, more generally consistent with an unfolding model like the Thurstone attitude measurement procedure rather than a cumulative model such as the Likert procedure and the typical item...

Topics: ERIC Archive, Attitudes, Likert Scales, Sampling, Test Items, Validity, Roberts, James S., Wedell,...

The generalized graded unfolding model (J. Roberts, J. Donoghue, and J. Laughlin, 1998, 1999) is an item response theory model designed to unfold polytomous responses. The model is based on a proximity relation that postulates higher levels of expected agreement with a given statement to the extent that a respondent is located close to the statement on a unidimensional latent continuum. J. Roberts and others (1998) have examined the recovery of item and person parameters from the generalized...

Topics: ERIC Archive, Attitude Measures, Estimation (Mathematics), Item Response Theory, Simulation,...

The generalized graded unfolding model (GGUM) (J. Roberts, J. Donoghue, and J. Laughlin, 1998) is an item response theory model designed to analyze binary or graded responses that are based on a proximity relation. The purpose of this study was to assess conditions under which item parameter estimation accuracy increases or decreases, with special attention paid to the influence that a given item parameter value has on the estimation of another item parameter. This assessment was based on a...

Topics: ERIC Archive, Estimation (Mathematics), Item Response Theory, Maximum Likelihood Statistics, Sample...

Binary or graded disagree-agree responses to attitude items are often collected for the purpose of attitude measurement. Although such data are sometimes analyzed with cumulative measurement models, recent investigations suggest that unfolding models are more appropriate (J. S. Roberts, 1995; W. H. Van Schuur and H. A. L. Kiers, 1994). Advances in item response theory (IRT) have led to the development of several parametric unfolding models for binary data (D. Andrich, 1988; Andrich and G. Luo,...

Topics: ERIC Archive, Attitude Measures, Estimation (Mathematics), Item Response Theory, Mathematical...