Fairness in language assessment: What can the Rasch model offer?

Drawing upon discussions of fairness in the field of language assessment, this systematic review study explores how the Rasch model has been used to investigate and enhance fairness in language assessment. To that end, we collected and systematically reviewed the empirical studies that used the Rasch model, published in four leading journals in the field from 2000 to 2018. A total of 139 articles were collected and subsequently coded in NVivo 11, using the open coding method. In addition, matrix coding analysis was implemented to explore the relationship between the topics that were identified and the language constructs that constituted the focus of the collected articles. Five broad themes were extracted from the coding process, including: 1) rater effects; 2) language test design and evaluation; 3) differential group performance; 4) evaluation of rating criteria, and 5) standard setting. Representative studies under each category were used to illustrate how the Rasch model was utilised to investigate test fairness. Findings of this study have important implications for language assessment development and evaluation. In addition, the findings also identified a few avenues in the application of the Rasch model which language assessment researchers should explore in future studies.