This research evaluated the effectiveness of identifying students’ real gains through the application of four commonly used equating methods: concurrent calibration (CC) equating, fixed common item parameter (FCIP) equating, Stocking and Lord test characteristic curve (TCC) equating, and mean/sigma (M/S) equating. The performance of the four procedures was evaluated using simulated data for a t...

Frequency estimation (also called post-stratification) is an equating method employed under the common-item nonequivalent groups design. A modified frequency estimation method is proposed here, based on altering one of the traditional assumptions in frequency estimation in order to correct for equating bias. A simulation study was carried out to compare equating errors for the modified frequenc...

The present study aims to compare the Kernel equating and local methods in observed score equating. Functions error estimates regarding difference between raw equated scores by Stocking-Lord Haebara true-score were examined Item Response Theory Observed Score Equating. Therefore, 5, 10, 15 external anchor items used, obtained from two forms based on 2PL model. R (version 3.5.3.) programming sof...

The passing rate of the Medical Licensing Examination has been variable, which probably originated from the difference in the difficulty of items and/or difference in the ability level of examinees. We tried to explain the origin of the difference using the test equating method based on the item response theory. The number of items and examinees were 500, 3,647 in 2003 and 550, 3,879 in 2004. C...

According to the equating guidelines, a set of common items should be a mini version of the total test in terms of content and statistical representation (Kolen & Brennan, 2004). Differences between vertical scaling and equating would suggest that these guidelines may not apply to vertical scaling in the same way that they apply to equating. This study investigated how well the guideline of con...

The R package kequate enables observed-score equating using the kernel method of test equating. We present the recent developments of kequate, which provide additional support for item-response theory observed score equating using 2-PL and 3-PL models in the equivalent groups design and non-equivalent groups with anchor test design using chain equating. The implementation also allows for local ...

Creating a vertical scale involves several decisions on assessment designs and statistical analyses to determine the most appropriate vertical scale. This research study aims at investigating common item stability check procedures to arrive at vertical linking item sets that will produce the necessary constants for computing vertical theta (ability) estimates and scale scores on a vertical scal...