Efficacy Research
Using data and science to build a language learning app that actually works
At Duolingo, we're committed to developing a product that's not just fun and engaging, but also effective at teaching languages. Our dedicated research team combines expertise in language acquisition, assessment, and machine learning to ensure our app delivers real results.
Our Approach to Efficacy Research
Duolingo takes a data-driven approach to measuring and improving the effectiveness of our language courses. We conduct rigorous efficacy studies that adhere to scientific standards, and we're transparent about our methodologies and findings.
Our research encompasses both internal and external studies:
- Internal Studies: Our team analyzes user data, A/B tests new features, and uses machine learning to optimize learning outcomes.
- External Research: We collaborate with universities and independent researchers to validate our approaches and ensure objectivity.
- User Testing: We regularly collect feedback from learners through surveys, interviews, and usability testing.
Key Findings from Our Research
Learning Outcomes
Our research consistently shows that active Duolingo users achieve language proficiency comparable to that gained through university language courses:
The average time it takes Duolingo learners to complete enough material to cover a full semester of university language instruction
The amount of daily practice we recommend for consistent progress in language acquisition
Language Skills Development
Our studies measure progress across four key language skills:
Reading
Writing
Listening
Speaking
Recent Research Publications
Our team regularly publishes research findings to contribute to the scientific understanding of language learning. Here are some of our recent publications:
Como o Little Pilgrim ensina inglês através de histórias bíblicas
Equipe Pedagógica Little Pilgrim • 2023
Um estudo abrangente mostrando que a prática regular com o Little Pilgrim proporciona melhorias significativas em habilidades de leitura, escrita, compreensão e fala em inglês, enquanto fortalece valores cristãos.
Read full paper →Melhorando a Eficácia do Little Pilgrim com Testes e Práticas Espaçadas
Silva, M., Santos, P., & Oliveira, R. • 2022
Esta pesquisa demonstra que a incorporação de testes e práticas espaçadas dentro do percurso de aprendizagem do Little Pilgrim melhora significativamente a retenção a longo prazo.
Read full paper →Aprendizes de Inglês usando Little Pilgrim
Silva, C. & Martins, E. • 2021
Um estudo mostrando que aprendizes iniciantes de inglês podem alcançar proficiência comparável à de estudantes de inglês em universidades em um período similar usando a metodologia de histórias bíblicas.
Read full paper →Medindo a Eficácia dos Cursos de Inglês do Little Pilgrim
Oliveira, R. & Costa, L. • 2020
Pesquisa mostrando que usuários do Little Pilgrim experimentam melhoria significativa nas habilidades linguísticas após completar o material do curso, medido por testes padronizados de proficiência.
Read full paper →Duolingo English Test Validation
In addition to our language courses, we've extensively validated the Duolingo English Test (DET), which is now accepted by over 3,000 institutions worldwide as an alternative to traditional English proficiency tests:
- The DET shows strong correlations with established tests like TOEFL and IELTS
- Independent studies confirm the reliability and validity of the test scores
- A Technical Manual is published to ensure transparency on test design and validity evidence
The Future of Efficacy Research at Duolingo
We're continually expanding our research initiatives, with upcoming studies on:
- Long-term retention of language skills
- Effectiveness of our courses for specific demographic groups
- Impact of different learning strategies on proficiency development
- Comparative analysis with traditional classroom learning
Our Commitment to Transparency
We believe in being transparent about both the strengths and limitations of our research. While our findings consistently demonstrate the effectiveness of Duolingo, we acknowledge that:
- Language learning is complex and influenced by many factors outside our control
- Individual results may vary based on motivation, prior knowledge, and learning environment
- App-based learning may be more effective for some language skills than others
We're dedicated to continuous improvement, using research findings to enhance our courses and provide the most effective language learning experience possible.