Author's response to reviews Title: Re-evaluating a vision-related quality of life questionnaire with item response theory (IRT) and differential item functioning (DIF) analyses Authors:

Re-evaluating a vision-related quality of life questionnaire with item response theory (IRT) and differential item functioning (DIF) analyses

BACKGROUND For the Low Vision Quality Of Life questionnaire (LVQOL) it is unknown whether the psychometric properties are satisfactory when an item response theory (IRT) perspective is considered. This study evaluates some essential psychometric properties of the LVQOL questionnaire in an IRT model, and investigates differential item functioning (DIF). METHODS Cross-sectional data were used f...

A confirmatory study of Differential Item Functioning on EFL reading comprehension

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...

Differential Item Functioning (DIF) in Terms of Gender in the Reading Comprehension Subtest of a High-Stakes Test

Validation is an important enterprise especially when a test is a high stakes one. Demographic variables like gender and field of study can affect test results and interpretations. Differential Item Functioning (DIF) is a way to make sure that a test does not favor one group of test takers over the others. This study investigated DIF in terms of gender in the reading comprehension subtest (35 i...

Author's response to reviews Title: Mokken Scale Analysis of Health and Well-being Questionnaire item responses: a Non-Parametric IRT Method in Empirical Research for Applied Health Researchers Authors:

Multiple Ways to Detect Differential Item Functioning in SAS

Differential item functioning (DIF), as an assessment tool, has been widely used in quantitative psychology, educational measurement, business management, and insurance and healthcare industries. The purpose of DIF analyses is to detect response differences of items in questionnaires, rating scales, or tests across different subgroups (e.g., gender), while controlling for ability level. There a...