Often, important decisions regarding accountability and placement of students in performance categories are made on the basis of test scores generated from tests, therefore, it is important to evaluate the validity of the inferences derived from test results. One of the threats to the validity of such inferences is aberrant responding. Several…

Many standardized tests are now administered via computer rather than paper-and-pencil format. The computer-based delivery mode brings with it certain advantages. One advantage is the ability to adapt the difficulty level of the test to the ability level of the test taker in what has been termed computerized adaptive testing (CAT). A second…

To efficiently assess multiple psychological constructs and to minimize the burden on respondents, psychologists increasingly use shortened versions of existing tests. However, compared to the longer test, a shorter test version may have a substantial impact on the reliability and the validity of the test scores in psychological research and…

In response to the low standards in short form development, Smith, McCarthy, and Anderson (2000) introduced a set of guidelines for the construction and evaluation of short forms of psychological tests. One of their recommendations requires researches to show that the variance overlap between the short form and its long form is adequate. This…

Orlando and Thissen (2000, 2003) proposed an item-fit index, S-X[superscript 2], for dichotomous item response theory (IRT) models, which has performed better than traditional item-fit statistics such as Yen's (1981) Q[subscript 1] and McKinley and Mill's (1985) G[superscript 2]. This study extends the utility of S-X[superscript 2] to polytomous…