The Routledge Handbook of Digital Language Assessment Innovations and Insights from the Duolingo English Test

List of figures                                                                                                                                                            i

List of tables                                                                                                                                                              ii

List of contributors                                                                                                                                                   iii

Acknowledgements                                                                                                                                                   iv

Foreword

Burr Settles

1.      Introduction: Digital Language Assessment in the Age of Accelerations

Ben Naismith

Part I: Test Theory

2.      Paradigm Shift: A Dynamic Ecosystem for AI-Driven Language Assessment

Jill Burstein, Alina A. von Davier

3.      The Empirical Void: Re-evaluating Trait-Based Tasks in Language Testing

Geoffrey T. LaFlair, Xun Yan

4.      Opportunity to Test: Geographical Access as a Neglected Aspect of Test Validity

Ramsey L. Cardwell, William C. M. Belzak

5.      Evolving Perspectives on Reading Assessment: Theory, Practice, and the Case of the Duolingo English Test

Xinyi Ma, Xun Yan

Part II: Test Development

6.      Compositional Automatic Item Generation: Developing Scalable, Valid, and Innovative Assessments

Yigal Attali, Andrew Runge, Yena Park, Sarah Goodwin, Geoffrey T. LaFlair

The Duolingo English Test Interactive Writing Task: A Conceptual and Evidence-based Innovation in Large-scale Writing Assessment. Mya Poe, Norbert Elliot

7.      Digital-first Content Development for Test Fairness

Yena Park, Jacqueline Church, Andrew Runge, Phoebe Mulcaire

8.      The DET Platform for Item eXperimentation, Iteration and Evaluation (PIXIE)

Xiaowan Zhang, Andrew Runge, Yigal Attali, Yena Park, Geoffrey T. LaFlair

Part III: Test Scoring

9.      Applications of Large Language Models in Automated Writing Evaluation

Nitin Madnani, Phoebe Mulcaire, Kai-Ling Lo

10.   Salient Pronunciation Features for L2 Oral Proficiency and Intelligibility: Implications for the DET’s Automated Scoring Algorithms

Masha Kostromitina, Okim Kang

11.   Maintaining the Meaning of Test Scores in a High-Volume Evolving Assessment

Steven W. Nydick, Manqian Liao, Siyuan M. Chen, J.R. Lockwood

12.   Calibration, Scoring, and Administration of a High-stakes Computerized Adaptive Test

James Sharpnack, Steven W. Nydick, J.R. Lockwood, Alexander Tsigler, Alina A. von Davier

Part IV: Test Infrastructure and Quality Assurance

13.   Software Architecture for a High-Stakes, On-demand, Digital-First Language Assessment

Kevin Yancey

14.   Securing the DET: Principles and Practices for a Secure Remote High-Stakes Test

Mizra B. Baig, Chenhao Niu, Yong-Siang Shih, Liangyu Chen

15.   Measuring Accuracy in Remote Proctoring Decisions

William C. M. Belzak, Yigal Attali

16.   Driving Innovation: Technical Program Management in AI-Enabled Digital Language Assessment

Neha Jain, Alina A. von Davier

Part V: Test Impact

17.   Investigating Duolingo English Test Washback: A Focus on Test Preparation Activities

Daniel R. Isbell, Ann Tai Choe, Daniel Holden, Ayano Kawasaki, Jieun Kim, Yoonseo Kim, Maggie McGehee, Hitoshi Nishizawa, Leeseul Park, Alexander F. Tang

18.   Breaking Barriers: How the Duolingo English Test Expands Access to Global Education

Emma McLeavey-Weeder, Adam Shuck

19.   Views on Malian English Pedagogy and Assessment and the DET Language Assessment Tasks: Finding Alignments and Opportunities Through Focus-group Research

Kadidja Koné, Paula Winke

20.   Building Trust in a Digital Test Through Marketing, Messaging, and Stakeholder Engagement

Sophie Wodzak, Ramsey L. Cardwell, Masha Kostromitina

Afterword

Innovations in Digital-First Adaptive Testing: The Duolingo English Test and the Future of Personalized Assessment

Alina A. von Davier, Stephen G. Sireci

Biography

Ben Naismith is a Staff Assessment Scientist at Duolingo where he works on research and development of the Duolingo English Test.

Alina A. von Davier is the Chief of Assessment at Duolingo. She has provided thought leadership to the Research and Development area for the Duolingo English Test for the past nine years.

Jill Burstein is a Principal Assessment Scientist at Duolingo, where she leads validity, efficacy, and responsible AI research for the Duolingo English Test.

Geoffrey T. LaFlair is a Principal Assessment Scientist at Duolingo where he leads Assessment Research and Development for the Duolingo English Test.

'Ten years after the Duolingo English Test began reshaping access to English proficiency testing, this handbook captures both the ambition and the evidence behind that work. It shows how digital assessment can be rigorous, fair, scalable, and deeply human.'

 - Luis von Ahn, Co-Founder and CEO at Duolingo

'A rigorous and timely contribution to digital assessment science. This handbook tackles AI-driven language testing where it matters: validity, fairness, security, and access. Grounded in evidence from the Duolingo English Test, it sets a new benchmark for responsible, scalable assessment design.'

- Virginia Dignum, Professor of Responsible AI, Umeå University; author of The AI Paradox (Princeton University Press, 2026)