Evolving software with an increasing number of features is harder to understand and thus harder to use. Software release planning has been concerned with planning these additions. Moreover, software of increasing size takes more effort to be maintained. In the domain of mobile apps, too much functionality can easily impact usability, maintainability, and resource consumption. Hence, it is important to understand the extent to which the law of continuous growth applies to mobile apps. Previous work showed that the deletion of functionality is common and sometimes driven by user reviews. However, it is not known if these deletions are visible or important to the app users. In this study, we performed a survey study with 297 mobile app users to understand the significance of functionality deletion for them. Our results showed that for the majority of users, the deletion of features corresponds with negative sentiments and change in usage and even churn. Motivated by these preliminary results, we propose RADIATION to input user reviews and recommend if any functionality should be deleted from an app's User Interface (UI). We evaluate RADIATION using historical data and surveying developers' opinions. From the analysis of 190,062 reviews from 115 randomly selected apps, we show that RADIATION can recommend functionality deletion with an average F-Score of 74% and if sufficiently many negative user reviews suggest so.

翻译：持续增加功能数量的软件变得更难理解，从而也更难使用。软件发布规划一直关注这些功能添加的计划。此外，软件规模越大，维护所需工作量也越大。在移动应用领域，过多功能容易影响可用性、可维护性和资源消耗。因此，理解持续增长定律在多大程度上适用于移动应用至关重要。先前研究表明，功能删除现象普遍存在，且有时由用户评价驱动。然而，尚不清楚这些删除对应用用户是否可见或重要。本研究通过对297名移动应用用户进行问卷调查，探究功能删除对他们的重要性。结果显示，对大多数用户而言，功能删除与负面情绪、使用行为变化乃至流失相关。基于这些初步发现，我们提出RADIATION方法，该方法可输入用户评价并推荐应从应用用户界面(UI)中删除哪些功能。我们利用历史数据并调查开发者意见对RADIATION进行评估。通过对115个随机选取应用的190,062条评价的分析，我们表明RADIATION能够以平均74%的F值推荐功能删除，且当足够多负面用户评价提出此建议时表现更佳。