The goal of this study was to design a mobile application to address the challenge of the lack of quality English-speaking lessons in South Korean middle and high schools. The study was conducted because providing quality English speaking lessons in large size classes arguably could foster equal access to acquiring English speaking skills in public education settings. WikiTalki, a mobile application developed in this study, is a classroom assistance tool that expands students' verbal practice opportunities and enables them to receive personalized peer feedback on their speaking performance. The development process of WikiTalki followed the design-based research (DBR) approach and was conducted in three iterations of design, development, and test. An empirical study was conducted to assess the application's effectiveness in terms of students’ participation, self-efficacy, achievement in oral speech, and perceived English-speaking success. Significant findings of the study were: recording and sharing function increased learner participation in large-sized English classes; peer feedback tended to promote collaborative learning; continuous refinement of the application design enhanced the quality of instructional design and usability.

这项研究的目的是设计一种移动应用程序，以解决韩国初中和高中英语口语课质量不足的挑战。进行这项研究是因为在大型课堂上提供优质的英语口语课可以促进在公共教育环境中获得英语口语技能的平等机会。这项研究中开发的移动应用程序WikiTalki是一种课堂辅助工具，可扩展学生的口头练习机会，并使他们能够收到有关其口语表现的个性化同peer反馈。WikiTalki的开发过程遵循基于设计的研究（DBR）方法，并在设计，开发和测试的三个迭代中进行。进行了一项实证研究，从学生的参与程度，自我效能，口语成绩和英语口语能力方面评估了该应用程序的有效性。该研究的重要发现是：记录和共享功能增加了学习者对大型英语课的参与；同伴反馈倾向于促进协作学习；应用程序设计的不断完善提高了教学设计的质量和可用性。