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 13. The eleven subtests of this battery cover such areas as vocabulary, reading comprehension, language, mathematics and work-study skills, and have multiple choice formats, with four alternatives, except for one subtest in which there are five. After the initial tabulation, which includes various frequency distributions and the evaluation of its results, the elimination of certain examinees, who obviously skipped excessive numbers of items, is decided. An important question is whether the examinees' behavior fits the Knowledge and Random Guessing Principle, and then the three-parameter normal ogive or logistic model. The chi-square goodness of fit test provides surprisingly little support. Index k*, which was introduced on an earlier stag of this research, was also used for this purpose. (Author/BW)