| Abstract: | This paper discusses various issues involved in using the Rasch model with multiple choice tests. By presenting a modified test that is much more powerful, the value of Wright and Panchapakesan's test as evidence of model fit is shown to be questionable. According to the new test, the model failed to fit 68% of the items in the Anchor Test Study. Effects of such misfit on test equating are demonstrated. Results of some past studies purporting to support the Rasch model are shown to be irrelevant, or to yield the conclusion that the Rasch model did not fit the data. Issues like "objectivity" and consistent estimation are shown to be unimportant in selection of a latent trait model. Thus, available evidence shows the Rasch model to be unsuitable for multiple choice items. |
