Language Learning ISSN 0023-8333 METHODS SHOWCASE ARTICLE The Lang-Track-App: Open-Source Tools for Implementing the Experience Sampling Method in Second Language Acquisition Research Henriette L. Arndt (she/her) , Jonas Granfeldt (he/him) , and Marianne Gullberg (she/her) Lund University Abstract: This paper introduces the Lang-Track-App, a smartphone application and backend system to aid second language acquisition researchers in implementing the experience sampling method (ESM). Surveying research participants with the Lang- Track-App multiple times per day can yield exceptionally rich data that can be analyzed CRediT author statement – Henriette Arndt: conceptualization (supporting); methodology (equal); investigation (lead); formal analysis (lead); writing (lead). Jonas Granfeldt: conceptual- ization (lead); methodology (equal); investigation (supporting); project administration (lead); writ- ing – reviewing & editing (supporting). Marianne Gullberg: conceptualization (lead); method- ology (equal); project administration (supporting); writing – reviewing & editing (supporting). Stephan Björck: software (equal). Josef Granqvist: software (equal). A one-page Accessible Summary of this article in non-technical language is freely available in the Supporting Information online and at https://oasis-database.org We gratefully acknowledge Stephan Björck and Josef Granqvist’s work on developing the Lang- Track-App software. The Lang-Track-App project was funded by the Marcus and Amalia Wallen- berg Foundation (grant number MAW 2018.0025). We also gratefully acknowledge support from the Lund University Humanities Lab. We thank the reviewers and editor for their helpful com- ments on previous versions of this manuscript. In addition, we express our thanks for the fruitful and stimulating discussions that we had while working on the Study Abroad Research in European Perspectives (SAREP) COST Action 15130 led by Professor Martin Howard, University of Cork, Ireland. Correspondence concerning this article should be addressed to Henriette Arndt, Lund Univer- sity Humanities Lab, Box 201, Lund, 221 00, Sweden. Email: henriette.arndt@humlab.lu.se The handling editor for this manuscript was Kris Kyle. This is an open access article under the terms of the Creative Commons Attribution-NonCom- mercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. Language Learning 00:0, December 2022, pp. 1–35 1 © 2022 The Authors. Language Learning published by Wiley Periodicals LLC on behalf of Language Learning Research Club, University of Michigan. DOI: 10.1111/lang.12555 14679922, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/lang.12555 by Lund University, Wiley Online Library on [20/12/2022]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License