Code comments are important for program comprehension, development, and maintenance tasks. Given the varying standards for code comments, and their unstructured or semi-structured nature, developers get easily confused (especially novice developers) about which convention(s) to follow, or what tools to use while writing code documentation. Thus, they post related questions on external online sources to seek better commenting practices. In this paper, we analyze code comment discussions on online sources such as Stack Overflow (SO) and Quora to shed some light on the questions developers ask about commenting practices. We apply Latent Dirichlet Allocation (LDA) to identify emerging topics concerning code comments. Then we manually analyze a statistically significant sample set of posts to derive a taxonomy that provides an overview of the developer questions about commenting practices.Our results highlight that on SO nearly 40% of the questions mention how to write or process comments in documentation tools and environments, and nearly 20% of the questions are about potential limitations and possibilities of documentation tools to add automatically and consistently more information in comments. On the other hand, on Quora, developer questions focus more on background information (35% of the questions) or asking opinions (16% of the questions) about code comments. We found that (i) not all aspects of comments are covered in coding style guidelines, e.g., how to add a specific type of information, (ii) developers need support in learning the syntax and format conventions to add various types of information in comments, and (iii) developers are interested in various automated strategies for comments such as detection of bad comments, or verify comment style automatically, but lack tool support to do that.

To perform various development and maintenance tasks, developers frequently seek information on various sources such as mailing lists, Stack Overflow (SO), and Quora. Researchers analyze these sources to understand developer information needs in these tasks. However, extracting and preprocessing unstructured data from various sources, building and maintaining a reusable dataset is often a time-consuming and iterative process. Additionally, the lack of tools for automating this data analysis process complicates the task to reproduce previous results or datasets.To address these concerns we propose Makar, which provides various data extraction and preprocessing methods to support researchers in conducting reproducible multi-source studies. To evaluate Makar, we conduct a case study that analyzes code comment related discussions from SO, Quora, and mailing lists. Our results show that Makar is helpful for preparing reproducible datasets from multiple sources with little effort, and for identifying the relevant data to answer specific research questions in a shorter time compared to state-of-the-art tools, which is of critical importance for studies based on unstructured data. Tool webpage: https://github.com/maethub/makar.