The overall aim was to examine effects of differences in group ability and features of the anchor test form on equating bias and the standard error of equating (SEE) using both real and simulated data. Chained kernel equating, Postratification kernel equating, and Circle-arc equating were studied. A college admissions test with four different…

Purpose: This study aims to compare the performances of Item Response Theory (IRT) equating and kernel equating (KE) methods based on equating errors (RMSD) and standard error of equating (SEE) using the anchor item nonequivalent groups design. Method: Within this scope, a set of conditions, including ability distribution, type of anchor items…

The aim of this study was to determine the effect of chance success on test equalization. For this purpose, artificially generated 500 and 1000 sample size data sets were synchronized using linear equalization and equal percentage equalization methods. In the data which were produced as a simulative, a total of four cases were created with no…

The aim of this study was to compare, by simulation, the accuracy of mapping a cut-score from one test to another by expert judgement (using the Angoff method) versus the accuracy with a small-sample equating method (chained linear equating). As expected, the standard-setting method resulted in more accurate equating when we assumed a higher level…

This report provides evidence of the substantive and structural validity of the Knowledge for Teaching Elementary Fractions Test. Field-test data were gathered with a sample of 241 elementary educators, including teachers, administrators, and instructional support personnel, in spring 2017, as part of a larger study involving a multisite…

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…

Two different types of anchors are investigated in this study: a mini-version anchor and an anchor that has a less spread of difficulty than the tests to be equated. The latter is referred to as a midi anchor. The impact of these two different types of anchors on observed score equating are evaluated and compared with respect to systematic error…

Test equating is a statistical procedure for adjusting for test form differences in difficulty in a standardized assessment. Equating results are supposed to hold for a specified target population (Kolen & Brennan, 2004; von Davier, Holland, & Thayer, 2004) and to be (relatively) independent of the subpopulations from the target population (see…

This study explores the use of a different type of anchor, a "midi anchor", that has a smaller spread of item difficulties than the tests to be equated, and then contrasts its use with the use of a "mini anchor". The impact of different anchors on observed score equating were evaluated and compared with respect to systematic…

It is a widely held belief that anchor tests should be miniature versions (i.e., minitests), with respect to content and statistical characteristics of the tests being equated. This paper examines the foundations for this belief. It examines the requirement of statistical representativeness of anchor tests that are content representative. The…

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)

This study explores the relative merits of a potentially useful item response theory (IRT) linking design: using a single set of anchor items with fixed common item parameters (FCIP) during the calibration process. An empirical study was conducted to investigate the appropriateness of this linking design using 6 groups of students taking 6 forms…

The analytically derived asymptotic standard errors (SEs) of maximum likelihood (ML) item estimates can be approximated by a mathematical function without examinees' responses to test items, and the empirically determined SEs of marginal maximum likelihood estimation (MMLE)/Bayesian item estimates can be obtained when the same set of items is…

The efficacy of employing subsets of items from a calibrated item pool to estimate the Rasch model person parameters was investigated. Specifically, the degree of invariance of Rasch model ability-parameter estimates was examined across differing collections of simulated items. The ability-parameter estimates were obtained from a simulation of…