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Article published In:
Journal of Second Language Studies
Vol. 7:1 (2024) ► pp.1–43

The effects of frequency, duration, and intensity on L2 learning through Duolingo

A natural experiment

| East Carolina University , United States
| Northern Arizona University , United States

Instructed second language (L2) research has frequently addressed the effects of spacing, or, alternatively, the distribution of practice effects. The present study addresses Rogers and Cheung’s (2021) concerns about the ecological validity of such work via a natural experiment (Craig et al., 2017). Learners’ self-determined exposure and in-app behavior were examined in relation to language gains over time. Duolingo learners of Spanish or French (N = 287) completed a background questionnaire, scales measuring L2 motivation and grit, and two tests of L2 proficiency before and after a six-month period of user-controlled app usage. Total minutes of app exposure exhibited a correlation with written but not oral proficiency gains. More dependable correlates of gains were frequency- and curriculum-oriented measures. Additionally, L2 grit and motivation were weakly to moderately correlated with several in-app behaviors. We conclude with implications for how apps can best be leveraged to produce L2 gains.

Keywords: distribution of practice, instructed SLA, mobile-assisted language learning, grit, Duolingo
Article outline
  • 1.Introduction
  • 2.Literature review
    • 2.1Distributed learning
    • 2.2Natural experiment
    • 2.3Mobile-assisted language learning
    • 2.4L2 grit and motivation
    • 2.5The Duolingo course structure
    • 2.6The present study
  • 3.Method
    • 3.1Participants
    • 3.2Instruments and materials
      • 1.Exposure/behavioral data
      • 2.Self-report data
      • 3.L2 proficiency
    • 3.3Procedure
    • 3.4Data analysis
  • 4.Results
    • 4.1Preliminary analyses: Scale data
    • 4.2Preliminary analyses: Proficiency data
    • 4.3RQ1: To what extent do learner gains differ when tested in the written vs. oral mode?
    • 4.4RQ2: To what extent are frequency, duration, and intensity of Duolingo app usage associated with gains in L2 Spanish and French?
    • 4.5RQ3: To what extent are L2 grit and motivation associated with the frequency, duration, and intensity with which learners use Duolingo?
    • 4.6RQ4: To what extent are L2 grit and motivation associated with gains in L2 Spanish and French?
  • 5.Discussion
  • 6.Conclusion
  • Acknowledgements
  • Notes
  • References
Available under the Creative Commons Attribution (CC BY) 4.0 license.

For any use beyond this license, please contact the publisher at [email protected].

Published online: 25 August 2023
DOI logo
https://doi.org/10.1075/jsls.00021.plo
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