Purpose: This study aimed to examine the impact of differential item functioning in anchor items on the group invariance in test equating for different sample sizes. Within this scope, the factors chosen to investigate the group invariance in test equating were sample size, frequency of sample size of subgroups, differential form of differential…

The main purpose of this study is to compare the test forms to the midi anchor test and the mini anchor test performance based on item response theory. The research was conducted with using simulated data which were generated based on Rasch model. In order to equate two test forms the anchor item nonequivalent groups (internal anchor test) was…

In this study, equating methods for random group design using small samples through factors such as sample size, difference in difficulty between forms, and guessing parameter was aimed for comparison. Moreover, which method gives better results under which conditions was also investigated. In this study, 5,000 dichotomous simulated data…

Research on equating with small samples has shown that methods with stronger assumptions and fewer statistical estimates can lead to decreased error in the estimated equating function. This article introduces a new approach to linear observed-score equating, one which provides flexible control over how form difficulty is assumed versus estimated…

This study examines the effect of differential item functioning (DIF) items on test equating through multilevel item response models (MIRMs) and traditional IRMs. The performances of three different equating models were investigated under 24 different simulation conditions, and the variables whose effects were examined included sample size, test…

This paper investigates four methods of linear equating under the common item nonequivalent groups design. Three of the methods are well known: Tucker, Angoff-Levine, and Congeneric-Levine. A fourth method is presented as a variant of the Congeneric-Levine method. Using simulation data generated from the three-parameter logistic IRT model we…

The kernel method of test equating is a unified approach to test equating with some advantages over traditional equating methods. Therefore, it is important to evaluate in a comprehensive way the usefulness and appropriateness of the Kernel equating (KE) method, as well as its advantages and disadvantages compared with several popular item…

Restricted equating samples are often used to equate test results. Previously eligible students may be excluded because this group of students is not stable from year to year and their inclusion may bias the results. The present study evaluated the impact of including previously eligible students in the equating samples, where the percentage of…

The purpose of this research was to compare the equating performance of various equating procedures for the multidimensional tests. To examine the various equating procedures, simulated data sets were used that were generated based on a multidimensional item response theory (MIRT) framework. Various equating procedures were examined, including…

The purpose of this article is to describe passage effects on "Dynamic Indicators of Basic Early Literacy Skills--Next Edition Oral Reading Fluency" ("DIBELS Next ORF") progress-monitoring measures for Grades 1 through 6. Approximately 572 students per grade (total "N" with at least one data point = 3,092) read all…

The purpose of this study was to evaluate the combined effects of reduced equating sample size and shortened anchor test length on item response theory (IRT)-based linking and equating results. Data from two independent operational forms of a large-scale testing program were used to establish the baseline results for evaluating the results from…

The Non-Equivalent groups with Anchor Test equating (NEAT) design is a widely used equating design in large scale testing that involves two groups that do not have to be of equal ability. One group P gets form X and a group of items A and the other group Q gets form Y and the same group of items A. One of the most commonly used equating methods in…

Small sample equating remains a largely unexplored area of research. This study attempts to fill in some of the research gaps via a large-scale, IRT-based simulation study that evaluates the performance of seven small-sample equating methods under various test characteristic and sampling conditions. The equating methods considered are typically…

This study investigated the impact of the coding scheme on IRT-based true score equating under a common-item nonequivalent groups design. Two different coding schemes under investigation were carried out by assigning either a zero or a blank to a missing item response in the equating data. The investigation involved a comparison study using actual…

A series of resampling studies was conducted to compare the accuracy of equating in a common item design using four different methods: chained equipercentile equating of smoothed distributions, chained linear equating, chained mean equating, and the circle-arc method. Four operational test forms, each containing more than 100 items, were used for…