A Study of the Characteristics of

Developers′ Activities in GitHub

2013/12/2

Saya Onoue, Hideaki Hata, Ken-ichi Matsumoto

Software Engineering Laboratory

Nara Institute of Science and Technology in Japan

What kind of developers are there?

2http://techiferous.com/2011/08/are-you-a-good-programmer/

http://www.techrepublic.com/blog/10-things/10-types-of-programmers-youll-encounter-in-the-field/

Cowboy

Fast worker

Sorcerer

Derive a program

Ninja

Hidden MVP

This Study

Goal

– Understand the different types of developers and

the ways that they make their contributions

Method

– Collect data from GitHub

– Analyze that data to investigate the characteristics

of the activities of real developers.

3

What is GitHub?

• Web-based hosting service for software

development projects that use the Git revision

control system.

– Social networking service for developers

• GitHub API

– We can collect various events about developers′

activities.

4

GitHub Developers′ Activities

5

• Code – related

– Create, Delete, Push, Fork,

PullRequest,

• Comment – related

– CommitComment,

PullRequestReviewComment,

IssueComment

• Issue – related*

– Issues

Code Issue

CommitComment

PullRequest

ReviewComment

Issue

Comment

Dev

Create

Delete

Push

Fork

PullRequest

Issues

*: contribute problems or questions

The data collection procedure

I. Select Projects

– Select active project for this study in GitHub

II. Identify Developers

– Identify developers in the selected project

III. Extract activity events

– Using the GitHub APIs, get specific events for the

developers

6

I. Select Projects

• We selected two projects for this study

– They were active projects on GitHub

7

Project Language Commits Forks Contributors

node JavaScript 8,974 4,572 447

jQuery JavaScript 5,270 4,587 168

II. Identify Developers

8

• We limited the contributors to developers

who have made more than 100 commits.

– node: 9 developers

– jQuery: 10 developers

III. Extract Activity Events• GitHub has 18 different types of activity events

• We selected 8 events since others occur rarely

• collect last 300 events

– Events of all projects that participateEvents Outline

Create created repository, branch, or tag.

Delete deleted branch or tag.

PullRequest request a change in the repository

Push upload a change history

CommitComment make statement Commit

IssueComment make statement Issues

PullRequestReviewComment make statement PullRequest

Issues contribute problems or questions

coding

commenting

9

The Research Questions

1. What events do developers cause?

2. When do developers work?

3. How much do developers work?

10

1. What events do developers cause?1/2

11Many commenting Many coding Balanced events

Coding, Commenting, and Issue Handling

1. What events do developers cause?2/2

• Different developers contribute differently

• There are various contributors in the projects

12

node N jQuery N

Code 2 Code 3

Comment 1 Comment 2

Code,Comment 4 Code/comment 2

Code,Comment,Issues 2 Code,Comment,Issues 3

2. When do developers work?1/2

13Dev 4

Dev 2

Dev 3

Dev 1

Employed

developers

Workdays

2. When do developers work?2/2

• Some work every day, and some work on a

specific day

• Some work on weekdays, They are actually

hired for this work

14

3.How much do developers work?1/2

15

A few weeks

Over a year

A few months

Frequencies of Activities (300 events)

3. How much do developers work?2/2

• There are large differences in frequency of

activities between developers

• We can find developers who are working actively,

and have contributed to the project for a long time

16

node N jQuery N

Days 1 Days 1

Weeks 3 Weeks 2

Months 3 Months 6

Years 2 Years 1

A summary of developer characteristics

17

Project Developer Majority Activities Frequencies

node

Dev 1 Code,Comments,Issues node project Years

Dev 2 Code,Comments node and others Weeks

・・・

Dev 3 Code node project Weeks

jQuery

Dev 4 Code,Comments Only Other projects Months

・・・

Dev 5 Comments jQuery project Months

Dev 6 Code,Comments,Issues Only other project A years

• Some of the characteristics of developers’

activities

Conclusion and Future work

• We analyzed the developers′ activities in GitHub.

And found some characteristics of developers.

– Different developers contribute differently

– Some work every day, and a specific day

– There is a large difference in activity frequencies by

developers

• Future work

– Detailed analysis with more data

– Project management based on developers’

characteristics 18