This article describes the National Center Test for University Admissions, a unified national test in Japan, which is taken by 500,000 students every year. It states that implementation of the Center Test began in 1990, with the English component consisting only of the written section until 2005, when the listening section was first implemented…

Because latent trait models require that large numbers of items be calibrated or that testing of the same large group be repeated, item parameter estimates are often obtained by administering separate tests to different groups and "linking" the results to construct an adequate item pool. Four issues were studied, based upon the analysis…

It is important to estimate the number of examinees who reached a test item, because item difficulty is defined by the number who answered correctly divided by the number who reached the item. A new method is presented and compared to the previously used definition of three categories of response to an item: (1) answered; (2) omitted--a…