the university of tehran english proficiency test (utept) is a high-stakes entrance examination taken by more than 10,000 master’s degree holders annually. the examinees’ scores have a significant influence on the final decisions concerning admission to the university of tehran ph.d. programs. as a test validation investigation, the present study, which is a bias detection research in nature, u...

Previous methodological and applied studies that used binary logistic regression (LR) for detection of differential item functioning (DIF) in dichotomously scored items either did not report an effect size or did not employ several useful measures of DIF magnitude derived from the LR model. Equations are provided for these effect size indices. Using two large data sets, the authors demonstrate ...

The  present  study  aimed  at  investigating  DIF  sources  on  an  EFL  reading  comprehension test.  Accordingly,  2  DIF  detection  methods,  logistic  regression  (LR)  and  item  response theory  (IRT),  were  used  to  flag  emergent  DIF  of  203  (110  females  &  93  males)  Iranian EFL examinees’ performance on a reading comprehension test. Seven hypothetical DIF sources were examin...

To date, many studies have been conducted to compare the performance of different DIF procedures using simulated data sets. However, some results from these simulation studies are inconsistent with one other (e.g., Hidalgo & López-Pina, 2004; Jodoin & Gierl, 2001). This study used real data to systematically investigate the consistencies of DIF detection and effect size among three widely-used ...

Extreme response styles (ERS) is prevalent in Likert- or rating-type data but previous research has not well-addressed their impact on differential item functioning (DIF) assessments. This study aimed to fill in the knowledge gap and examined their influence on the performances of logistic regression (LR) approaches in DIF detections, including the ordinal logistic regression (OLR) and the logi...

This paper defines the preliminary test estimator (PTE) of the univariate normal mean under the original as well as the Edgeworth size corrected Wald (W), likelihood ratio (LR) and Lagrange multiplier (LM) tests. The bias and mean squared error (MSE) functions of the estimators are derived. The conflicts among the biases and the MSEs of the PTEs under the three original and the size corrected t...