The results of data analysis based on the multiplicative binomial model (MLTBIN) are compared with dichotomous data analyzed by using the simple logistic model (SLM). Specifically, the paper focuses on the issues of fit to these Rasch Models and estimates of item difficulty. The data indicate that the SLM and MLTBIN are not comparable in the…

The dangers of overlooking time-honored cautions in the making causal interpretations of data analyses from correlational studies when using highly sophisticated computer programs and their associated techniques are discussed. (JKS)

The research on covariance structure analysis is reviewed, and various restrictions on the parameter matrices of the general model are delineated. Models employing two particular restrictions (where the matrix of weights is completely specified and is either scaled--by some unknown but estimable matrix of scaling weights--or unscaled) are…

Considers the study of similarities and differences in factor structures between different groups. (AG)

Estimation is by means of iterative convergence to maximum likelihood estimates, and two approaches to assessing fit of the model to sample data are discussed. Relation of this general probabilistic model to other, more restricted models is explored and three cases of the general model are applied to exemplary data. (Author/RC)

This paper will discuss the results of a series of computer simulations comparing the Rasch logistic model to a series of models departing to various degrees from its assumption of equal discrimination power for all items. The results have implications for test construction and test scoring, indicating how closely the conventional raw score…

A study was undertaken to develop guidelines for the interpretation of the parameters of three multidimensional item response theory models and to determine the relationship between the parameters and traditional concepts of item difficulty and discrimination. The three models considered were multidimensional extensions of the one-, two-, and…

The appropriateness of the use of the standardized residual (SR) to assess congruence between sample test item responses and the one parameter latent trait (Rasch) item characteristic curve is investigated. Latent trait theory is reviewed, as well as theory of the SR, the apparent error in calculating the expected distribution of the SR, and…

A numerical procedure is outlined for obtaining an interval estimate of a parameter in an empirical Bayes estimation problem. The case where each observed value x has a binomial distribution, conditional on a parameter zeta, is the only case considered. For each x, the parameter estimated is the expected value of zeta given x. The main purpose is…

A model and a computer program for performing conjoint measurement is developed. (AG)

A study was conducted to compare the quality of the item parameter estimates obtained from the ANCILLES and LOGIST estimation procedures using goodness of fit as a criterion. Statistics used to compare the fit included a chi-square statistic and a mean square deviation statistic. Other analyses performed included comparisons of the distributions…

To test for item bias, it must be determined whether an item fits the model. Two approaches to defining bias within the framework of the Rasch model are examined. One compares within-group fit mean squares and the other utilizes a between-group fit statistic. Results from both approaches overlap somewhat, but are distinct in many different but…

A computer program for solving the conditional likelihood equations arising in the Rasch model for questionnaires is described. The estimation method and the computational problems involved are described in a previous research report by Andersen, but a summary of those results are given in two sections of this paper. A working example is also…