主题：《Leaderboard Effect: Who, When, and How?》
摘要：We study the design of leaderboard for an online learning platform in order to help users finish their learning object, increase their activation and retention, and enlarge the user base of the platform. The online learning platform we study is an English-word-memorizing platform for Chinese learners, and it displays the learning hours of top ten users one day before. We show the existence of leaderboard effects during the learning process of users, i.e., users learn more when exposed to a longer leaderboard hour. Such effect exhibits a hump-shape as the user is moving towards the end of the book, with maximum value happened when users finish 60% of the process. The above reduced-form finding is consistent with the predictions in the goal literature studying the interplay of internal motivation and external motivation (e.g., Huang, 2018). Motivated by our reduced-form findings, we build a structural model which allows for rich heterogeneity in terms of base-line learning intensity, the position on the leaderboard referred, the leaderboard effects, and its variation along the learning process. Based on our model estimates and counterfactual analysis, we have the following advices:
(1) identify users who are not positively responsive to the leaderboard, and shut down the leaderboard on their screen (who);
(2) for each users, detect their specific period of learning process with positive leaderboard effect, and only show leaderboard during that period (when);
(3) show the optimal length of the leaderboard based on their heterogeneous referral position (how).
This paper shed light on the interface design of online learning websites, and it may also provide guidance for other websites with leaderboard.