When colleges and universities evaluate international applicants, English language proficiency tests play an important role in admissions decisions. Institutions want to be confident that the test scores they use provide a meaningful indication of students’ readiness to undertake academic work in English.
A new peer-reviewed study by Maggie McGehee and Daniel Isbell at the University of Hawai‘i at Mānoa (UHM) offers valuable insights. Published in Studies in Language Assessment, the research examined how Duolingo English Test (DET) scores relate to student performance compared to IELTS and TOEFL. The findings provide encouraging evidence for institutions that already accept DET, as well as those considering adding it as an option for applicants.
A closer look at the study
The study analyzed outcomes for 397 international students admitted to UHM in Fall 2022 or later, once the university had resumed primarily in-person instruction. Unlike previous research at highly selective institutions, this study was conducted at a large U.S. public research university with a higher acceptance rate. That context allowed researchers to examine a wider range of test scores, including lower-scoring students admitted on a conditional basis.
Researchers compared DET, IELTS, TOEFL, and test-exempt students at both the undergraduate and graduate levels. They analyzed correlations between test scores and first-year GPA, compared average GPAs across groups, and reviewed whether students experienced negative academic actions such as probation, warning, or withdrawal.
Academic performance was similar across test groups
The study’s results point to several important takeaways for institutions:
Comparable correlations across tests
Correlations between test scores and GPA were modest for all three exams, consistent with prior research. No substantive differences emerged between DET, IELTS, and TOEFL in terms of how strongly scores related to GPA.
Similar average GPAs
At both the graduate and undergraduate levels, there was no statistically significant difference in average GPAs across the four student subgroups.
| Test | Graduate students | Undergraduate students | ||
|---|---|---|---|---|
| Average GPA | Sample size | Average GPA | Sample size | |
| DET | 3.84 | 17 | 3.37 | 57 |
| IELTS | 3.88 | 25 | 3.31 | 19 |
| TOEFL | 3.73 | 43 | 3.53 | 16 |
| Exempt | 3.77 | 50 | 3.30 | 134 |
Comparable academic standing
Rates of academic warning, probation, or withdrawal were similar across DET, IELTS, and TOEFL groups. Interestingly, test-exempt students had the highest rates of academic difficulty, highlighting the importance of carefully determining test exemption criteria.
Strong outcomes among conditional admits
Students admitted conditionally with lower proficiency scores showed that success is still possible with proper support. In fact, graduate students admitted conditionally with DET scores achieved the highest average GPA of all subgroups (3.95). This finding also underscores that language proficiency is only one of many factors that impact students’ academic performance.
The takeaway: independent research supports the DET’s use in admissions
For admissions offices, the key question is whether a relatively new and innovative assessment like the DET provides the same confidence in student readiness as older tests. This study offers reassuring evidence that it does. On the whole, students admitted with DET scores performed just as well academically as those admitted with IELTS or TOEFL scores.
The findings also highlight an important policy consideration: certain criteria currently used to exempt students testing may not be sufficiently reliable indicators of readiness for academic work in English.
The McGehee and Isbell study adds to the growing body of independent, peer-reviewed research providing evidence for the valid use of DET scores in university admissions. For institutions that already accept the DET, these findings reinforce the soundness of that decision. For those considering adoption, the study offers further assurance that the DET can be a reliable and accessible option for evaluating international applicants.