[论文解读] A Large-scale Analysis of App Inventor Projects.

Nathalia da Cruz Alves, Christiane Gresse von Wangenheim+1 more|arXiv (Cornell University)|Jun 19, 2020

Teaching and Learning Programming参考文献 19被引用 1

一句话总结

本研究分析了来自公开画廊的88,606个App Inventor项目，以探究编程概念的使用情况及项目特征。研究发现，App Inventor项目在规模上差异显著，许多项目使用的编程积木多于设计组件，且事件的使用频率高于条件语句或循环——这一现象与Scratch存在差异，为计算教育课程设计提供了重要启示。

ABSTRACT

App Inventor is a popular block-based programming environment used by a wide audience, from K-12 to higher education, including end-users to create mobile applications to support their primary job or hobbies. Although learning computational thinking with App Inventor has been investigated, a question that remains is which programming concepts are typically used and how this compares to other block-based programming environments. Therefore, we explore the characteristics of App Inventor projects through a large-scale analysis of 88,606 apps from the App Inventor Gallery. We discovered that the size of App Inventor projects varies from projects with very few blocks to some surprisingly large projects with more than 60,000 blocks. In general, much fewer design components are used than programming blocks, as typically, to work properly, several programming blocks are necessary for each design component in an App Inventor project. In addition, we also compare our results with the analysis of 233,491 Scratch projects reported by Aivaloglou and Hermans [4]. Several differences can be observed, as in App Inventor projects events are more predominant, with lesser use of conditionals and loops. These findings may guide the decision on the adoption of App Inventor for teaching computing depending on the specific learning objectives or indicate the need for tailoring the curricula.

研究动机与目标

• 为了理解在大规模用户群体中，App Inventor项目里各种编程概念的普遍程度及其分布情况。
• 将App Inventor项目特征与其它积木式编程环境（尤其是Scratch）进行比较。
• 识别项目规模、组件使用情况及积木构成的模式，以指导App Inventor在教育中的应用。
• 通过识别真实世界App Inventor应用中最常使用的编程构造，为课程开发提供指导。

提出的方法

• 收集并分析来自App Inventor画廊的88,606个公开共享的App Inventor项目。
• 定量提取项目元数据，包括编程积木数量、设计组件数量、事件、条件语句和循环的数量。
• 将App Inventor项目统计数据与先前对233,491个Scratch项目的大型规模分析结果进行比较。
• 对编程构造进行分类与频率分析，以评估其在真实项目中的相对使用程度。

实验结果

研究问题

• RQ1 在App Inventor项目中，编程积木与设计组件的数量分布如何？
• RQ2 与Scratch相比，App Inventor中事件、条件语句和循环等编程构造的使用频率有何差异？
• RQ3 App Inventor项目在多大程度上依赖事件驱动逻辑，而非循环和条件语句等控制结构？
• RQ4 不同项目中编程积木与设计组件的比例如何变化？这反映了怎样的实现复杂性？

主要发现

• App Inventor项目规模从极小到极大不等，部分项目使用的编程积木超过60,000个。
• 在大多数项目中，编程积木的数量显著超过设计组件的数量，表明每个用户界面元素都伴随着复杂的逻辑。
• 事件是App Inventor项目中最常使用的编程构造，其次是使用频率较低的条件语句和循环。
• 与Scratch相比，App Inventor项目更强调事件驱动编程，对迭代和条件构造的依赖程度较低。