The document analyzes blogging behavior among developers in four open source communities. It finds that blogging is a regular activity where posts discuss high-level topics like requirements and integration. Blog posts occur most frequently after corrective commits and developers use blogs to elaborate on recent commit messages. Analysis of post content, frequency, and relationship to commits provides an empirical framework for understanding the role of blogs in software development.

1. How Do Developers Blog?An Exploratory Study Dennis Pagano, Technische Universität München Walid Maalej, Technische Universität München

3. Blog posts exhibit recurrent usage patterns and common topics

4. Relationship between developers’ blogging and committing behavior1 2

5. Outline Motivation 1 Research Setting 2 Research Results 3 Summary 4 Pagano, Maalej, May 2011 3 How Do Developers Blog? – MSR 2011

6. Motivation Many software developers publish information related to their work in blogs We do not know how they blog and what they blog We also do not understand the connection to “conventional” development activities Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 4 Towards empirical framework on the role of blogs and other social media in software engineering

7. Outline Motivation 1 Research Setting 2 Research Results 3 Summary 4 Pagano, Maalej, May 2011 5 How Do Developers Blog? – MSR 2011

12. Collected Data Sets Pagano, Maalej, May 2011 8 How Do Developers Blog? – MSR 2011

13. Outline Motivation 1 Research Setting 2 Research Results 3 Summary 4 Pagano, Maalej, May 2011 9 How Do Developers Blog? – MSR 2011

14. Blog Usage: Publishing Frequency Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 10 Mean time between successive posts within a community is about 8.1 hours Committersblog on average more frequently(every 26 days) than other bloggers (every 28 days) Committers use blogs for longer time periods (about 2.2 years) than other bloggers (about 1.6 years)

15. Blog Usage: Post Structure Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 11 Posts comprise 150 words on average 95% are shorter than 1,000 words 1.8% of posts contain source code paragraphs 80% of posts contain links Committers include more links to Wikis (11%) than other bloggers (8%) Committers more frequently link to other blogs (28%) than other bloggers (25%) 29% of posts contain images Committers post more screenshots (22%) than other bloggers (18%)

16. Findings on Blog Usage Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 12 Regular social activities in the studied open source communities 1 Posts are less frequent than commit messages but comprise more content 2 Posts rarely contain source code, but frequently high level information and images 3 Committers reuse more knowledge than other bloggers 4

17. Method Used to Analyze Blog Content Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 13 Set of words per community Common topic labels Topic category Functional requirements & domain concepts Requirements Non-functional requirements

18. Popular Topics Identified in Blogs Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 14

19. Topic Categories Identified in Blogs Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 15

20. Findings on Blog Content Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 16 1 More than half of all posts discuss requirements Source code and technical content is less popular 2 Blogs comprise more high-level than low-level concepts 3 Community-related topics are orthogonal to other topics 4

21. Blog Integration Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 17 Categories of Commits Before Blog Posts:

22. Blog Integration Results Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 18 Most blog posts occur after corrective commits (~36.5%), least after management commits (~19%) Conversely blog posts are more likely after corrective (2.6%) or management (2.3%) commits 15.5% of posts included information previously described in commit messages Dependency between commit messages and blog posts decreases with increasing time in-between

23. Findings on Blog Integration Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 19 Bug fixes and management activities are frequently shared with all stakeholders in a software community 1 Developers are more likely to publish information about their recent activities than about old activities 2

24. Outline Motivation 1 Research Setting 2 Research Results 3 Summary 4 Pagano, Maalej, May 2011 20 How Do Developers Blog? – MSR 2011

26. High level information(screenshots) and knowledge reuse (links)

27. Short documentations, tutorials, howtos

28. Integration of blogging (social) activities

31. Developers use blogs to elaborate recent commit messagesBlog Integration

32. Feedback, Questions, Suggestions and Collaboration are Welcome! Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 22 Dennis Pagano TUM pagano@cs.tum.edu Walid Maalej TUM maalejw@cs.tum.edu

33. BACKUPS Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 23

34. Blog Content – Most Popular Topics Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 24

35. Blog Integration Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 25 Frequencies of Commit Categories:

36. Blog Integration Blogging Probability after Commits Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 26

37. Blog Integration Time Dependencies between Blogs and Commits Pagano, Maalej, May 2011 How Do Developers Blog? – MSR 2011 27