The existence of outliers in the anchor items can be detrimental to the estimation of examinee ability and undermine the validity of score interpretation across forms. However, in practice, anchor item performance can become distorted due to various reasons. This study compares the performance of modified "INFIT" and "OUTFIT"…

In recent years, the interest in measuring growth in student ability in various subjects between different grades in school has increased. Therefore, good precision in the estimated growth is of importance. This paper aims to compare estimation methods and test designs when it comes to precision and bias of the estimated growth of mean ability…

The purpose of this study is to address the necessity of subscore equating and to evaluate the performance of various equating methods for subtests. Assuming the random groups design and number-correct scoring, this paper analyzed real data and simulated data with four study factors including test dimensionality, subtest length, form difference in…

In common-item equating the anchor block is generally built to represent a miniature form of the total test in terms of content and statistical specifications. The statistical properties frequently reflect equal mean and spread of item difficulty. Sinharay and Holland (2007) suggested that the requirement for equal spread of difficulty may be too…

The standard error of equating quantifies the variability in the estimation of an equating function. Because common items for deriving equated scores are treated as fixed, the only source of variability typically considered arises from the estimation of common-item parameters from responses of samples of examinees. Use of alternative, equally…

Potential benefits of using item response theory in test construction are evaluated using the experience and evidence accumulated during nine years of using a three-parameter model in the development of major achievement batteries. Topics addressed include error of measurement, test equating, item bias, and item difficulty. (TJH)

An experiment is reported in which 225 high school students were asked to choose among several multiple-choice items but then were required to answer them all. It is concluded that allowing choice while having fair tests is only possible when choice is irrelevant in terms of difficulty. (SLD)

Whether anchor item sets varying in difficulty and discrimination affect precision of cutting score equivalents generated through judge rescaling as much as equivalents from score equating was studied with 4 groups of experts and 250 and 1,000 examinees. Results indicate the robustness of judge rescaling and its superiority over equating. (SLD)