The first step of the data analysis with respect to the eventual application of the various new methods in latent trait theory is here initiated. The data are a set of approximately 500 item responses of each of 7,439 examinees to the Iowa Tests of Basic Skills, Form 6, on one of three difficulty levels, which correspond to the ages of 11, 12 and…

This study developed a hybrid of item response theory (IRT) models and latent class models, which combined the strengths of each type of model. The primary motivation for developing the new model is to describe characteristics of examinees' knowledge at the time of the examination. Hence, the application of the model lies mainly in so-called…

When learning is taking place, students test their hypotheses and evaluate them, and modify their current theories on the basis of new information. This phenomenon is known as "hypothesis testing view" or "theory changes." Many students change their rules to another while they are taking a test. This study introduced a new…

In order to evaluate our methods and approaches of estimating the operating characteristics of discrete item responses, it is necessary to try other comparable methods on similar sets of data. LOGIST 5 was taken up for this reason, and was tried upon the hypothetical test items, which follow the normal ogive model and were used frequently in…

Simple sum procedure of the conditional PDF approach (plausiblity of distractor function) combined with the normal approach method was applied for estimating the plausibility functions of the distractors of the Level II vocabulary subtest items of the Iowa Tests of Basic Skills. In so doing, the normal ogive model was adopted for the correct…

Recent developments in dichotomous factor analysis based on multidimensional item response models (Bock and Aitkin, 1981; Muthen, 1978) provide an effective method for exploring the dimensionality of questionnaire items. Implemented in the TESTFACT program, this "full information" item factor analysis accounts not only for the pairwise…

The use of a three-parameter logistic model for applying latent trait theory has become more popular because of the availability of computer programs. The program Logist 5 can be used not only for the item parameter estimation in the three-parameter logistic model, but also in the two parameter logistic model by setting the third parameter equal…

The feasibility of pre-equating, or establishing conversions from raw to scaled scores through the use of pretest data before operationally administering a test, was investigated for the Scholastic Aptitude Test (SAT). Item-response theory based equating methods were used to estimate item parameters on SAT pretest data, instead of using final form…

The stability of Rasch test item difficulty parameters was investigated under varying conditions. Data were taken from a mathematics achievement test administered to over 2,000 Australian students. The experiments included: (1) relative stability of the Rasch, traditional, and z-item difficulty parameters using different sample sizes and designs;…