How Does the Shift to GitHub Impact Project Collaboration?

Transcript

1. How Does the Shift to GitHub
   Impact Project
   Collaboration?
   Gustavo Pinto
   I. Steinmacher M. Gerosa
   F. Fronchetti D. Alencar
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3. Why?
   http://programmers.stackexchange.com/questions/164618
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4. Why?
   http://programmers.stackexchange.com/questions/164618
   Is simple
   Is easy to use
   Because Github:
   Offers DVCS support
   has the PR system
   increases collaboration
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5. 5
   Does Github really
   increase collaboration?
   

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6. Active: >= 1 commit in the last 12
   months
   Popular: > 10.000 stars
   Non-trival: > 10.000 LoC
   Obviously: Migrated to Github
   Projects Selection
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7. Active, popular, non-trivial
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8. Active, popular, non-trivial
   Projects Prog. Language Moved to Github LoC Age
   Ruby C 02/2010 1,001K 18
   mongodb C++ 01/2009 2,104K 9
   Jenkins Java 11/2010 191K 10
   Rails Ruby 04/2008 203K 12
   Joomla! PHP 09/2011 610K 11
   jQuery JavaScript 04/2009 41K 10
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9. Method: Two Steps
   1) Mining Software Repositories
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10. Method: Two Steps
    1) Mining Software Repositories
    2) Survey with developers
    Q1: What motivated the project to move to Github?
    Q2. Do you have any internal policy to attract
    newcomers?
    Q3: Does this snapshot make sense?
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11. How Does the Shift to
    GitHub Impact Project
    Collaboration?
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12. How Does the Shift to
    GitHub Impact Project
    Collaboration?
    In terms of:
    {• number of newcomers, active
    committers, contributions
    • number of pull-requests
    received
    • number of issues created
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13. Newcomers, active
    committers, contributions
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14. Committer
    # commiters
    p-value 0.001
    effect size 0.633 14
    

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15. Committer
    # commiters
    p-value 0.001
    effect size 0.633 15
    The number of committers increased significantly
    (effect size = 0.633)
    

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16. Contribution
    # commiters contributions
    p-value 0.001 0.001
    effect size 0.633 0.635 16
    The number of contributions increased significantly
    (effect size = 0.635)
    

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17. # commiters contributions newcomers
    p-value 0.001 0.001 0.001
    effect size 0.633 0.635 0.460
    Newcomer
    The number of newcomers increased significantly
    (effect size = 0.460)
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18. # commiters contributions newcomers
    p-value 0.001 0.001 0.001
    effect size 0.633 0.635 0.460
    Newcomer
    Rails core developer
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    We don't have any strong
    policy other than: be nice with
    newcomers, give them attention, good
    feedback and try to motivate them to
    solve their own problems.
    The number of newcomers increased significantly
    (effect size = 0.460)
    

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19. # commiters contributions newcomers
    p-value 0.001 0.001 0.006
    effect size 0.299 0.018 0.206
    The rise of active committer does not imply in the
    rise of contributions
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20. # commiters contributions newcomers
    Joomla!
    p-value 0.001 0.001 0.006
    effect size 0.299 0.018 0.206
    jQuery
    p-value 0.035 0.001 0.060
    effect size 0.066 0.144 0.160
    The migration to GitHub played a major role to the rise of
    contributions in only 2 out of the 6 studied projects
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    effect size: 0.018 effect size: 0.114
    

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21. Pull-Requests
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22. Pull Requests
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23. Pull Requests
    Several PRs are submitted, few got merged
    (3 out of the 1,223 Ruby PRs got merged)
    Merged PRs
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24. Pull Requests
    The number of PRs did not
    increase over time
    (in 5/6 of the projects)
    (again) Several PRs are
    submitted, few got merged
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25. Issues
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26. Issues
    Not all projects are
    using the issue
    tracking system
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27. Issues
    Initial effort
    required!
    Not all projects are
    using the issue
    tracking system
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28. In summary
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29. The rise of contributions is not
    straightforward
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30. Little effort was placed on policies
    for attracting or retaining
    newcomers
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31. 31
    Some projects have a high rate of
    PRs closed and not merged.
    If the project is not intended to use
    PRs, state this upfront!
    

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32. 32
    Some projects have a high rate of
    PRs closed and not merged.
    If the project is not intended to use
    PRs, state this upfront!
    

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33. Project members might expect an
    overhead on managing the issue
    tracking system
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34. 34
    THANKS
    

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35. How Does the Shift to GitHub
    Impact Project
    Collaboration?
    Gustavo Pinto
    I. Steinmacher M. Gerosa
    F. Fronchetti D. Alencar
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