GitHub has introduced gamification via personal achievements, whereby badges are unlocked and displayed on developers' personal profile pages in recognition of their development activities. In this paper, we present a mixed-methods empirical investigation to study the diffusion of personal badges in GitHub in addition to the effects of and the reactions to their introduction. First, we conducted an observational study by mining longitudinal data for over 6,000 developers and performed correlation as well as regression analysis. Then, we analyzed 33 answers to a survey and 312 GITHUB community discussions about personal badges to gauge how the community reacted to the introduction of the new feature. We found that most of the sampled developers own at least a badge, but we also observed an increasing number of users who choose to keep their profile private and opt out from displaying badges. Besides, badges are in general poorly correlated with developers' qualities and dispositions such as timeliness and desire to collaborate. We also found that, with the exception of the Starstruck badge and the number of followers, their introduction to GitHub had no effects. Finally, the reaction of the community has been in general mixed, as developers find them appealing in principle but without a clear purpose and hardly reflecting their abilities in the current form.

翻译：GitHub通过个人成就引入了游戏化机制，开发者可通过解锁徽章并将其展示在个人资料页面上，以表彰其开发活动。本文采用混合方法进行实证研究，探讨GitHub个人徽章的扩散情况、其引入带来的影响及社区反应。首先，我们通过挖掘超过6000名开发者的纵向数据开展观察性研究，进行了相关性分析和回归分析。随后，我们分析了33份问卷调查的回复及312场关于个人徽章的GitHub社区讨论，以评估社区对该新功能引入的反应。研究发现，大多数抽样开发者至少拥有一个徽章，但我们也观察到选择隐藏个人资料且不展示徽章的用户数量在增加。此外，徽章与开发者的品质和倾向（如及时性和协作意愿）普遍相关性较低。我们还发现，除Starstruck徽章和粉丝数量外，徽章的引入对GitHub未产生显著影响。最后，社区反应总体上褒贬不一——开发者认为徽章在原则上具有吸引力，但缺乏明确目的，且当前形式难以真实反映其能力。