A bibliometric analysis of research into the International English Language Testing System (IELTS)

Abstract

This study provides a bibliometric analysis of International English Language Testing System (IELTS) research from 1989 to 2024, incorporating 641 research documents. Among these, 482 were obtained from five online indices (Web of Science, Scopus, ERIC, EBSCOhost, Google Scholar) and 159 were identified manually (including 146 studies sponsored by the IELTS co-owners). The analysis focuses on patterns and trends in research topics, methodological approaches, publications and disciplinary areas, author-affiliated institutions and countries, and co-authorship. The results show that topics which were well-covered by researchers extended beyond psychometrics and validation of the testing system to include consequential factors, such as teaching and learning, academic/professional contexts, test preparation, and non-linguistic constructs (e.g., stakeholders’ attitudes, beliefs). Quantitative studies constituted the most common approach but were exceeded by (often well-cited) mixed-methods inquiries sponsored by the co-owners. Research authorship diversified from Anglophone to English as a Foreign Language (EFL)/English as a Second Language (ESL) contexts, reflecting a broader view of IELTS’s validity, warranting further exploration. Implications of the findings are discussed both for IELTS and language assessment research more generally.