This study investigated quasi-contributors in open source software projects. The researchers analyzed 21 popular open source projects on GitHub. They found that quasi-contributors, who made at least one rejected contribution, accounted for around 70% of all contributors. Common reasons for rejections included duplicated/superseded pull requests, a mismatch between the developer's and team's visions, and pull requests deemed not needed or not relevant. Quasi-contributors reported feeling demotivated after a rejection, especially if they disagreed with the decision. The results provide insights for open source maintainers, newcomers, and educators on how to improve acceptance of contributions.

1. Almost There: A Study on
Quasi-Contributors in Open Source
Software Projects
Igor STEINMACHER
@igorsteinmacher
Gustavo PINTO
@gustavopinto
Igor WIESE
@igorwiese
Marco GEROSA
@gerosa_marco

2. Sustainable OSS projects
2

3. 3

4. 4

5. Contributing to OSS
Many contributors
succeed when they
submit changes
5

6. Contributing to OSS
Some got some rejected
patches
6

7. Contributing to OSS
7

8. Quasi-contributors
Contributing to OSS
8

9. Goal
Investigate how and why quasi-contributorsfail
9

10. Research Questions
RQ1.How common are quasi-contributors
and quasi-contributions?
RQ2.Why were the quasi-contributions
not accepted?
RQ3.How do quasi-contributors perceive
nonacceptance?
10

11. angular
bitcoin
bootstrap
caffe
d3
django
docker
flask
jenkins
joomla!
jquery
Sampling kubernetes
laravel
mongo
opencv
rails
react
redis
scikit-learn
spring
tensorflow
11

12. Quasi-contributors
5,138
Quasi-contributors
234
Integrators
335 answers from
quasi-contributors
21 answers from
integrators
Mixed-Method Approach
Manualanalysis
263 PRs from
quasi-contributors 12

13. RQ2.Why were the quasi-
contributions not accepted?
RQ3.How do quasi-
contributors perceive
nonacceptance?
Mixed-Method Approach
Quasi-contributors
5,138
Quasi-contributors
234
Integrators
335 answers from
quasi-contributors
21 answers from
integrators
Manualanalysis
263 PRs from
quasi-contributors
RQ1.How common are
quasi-contributors and
quasi-contributions?
13

14. RQ1. How common? Considering all 21 projects:
→ 10,099 quasi-contributors
→ 14,623 actual contributors
14

15. RQ1. How common? ~85%
→
1attempt
15

16. "The fix I submitted remained unmerged
until someone else submitted the exact
same fix … the integrators accepted their
(identical) fix and closed mine.”
superseded/duplicatedpull-request(52/335)
[Gousios et al., 2014; Zhou et al., 2018]
“Other pull-requests fixed the same
issues as my pull-requests”
RQ2. Reasons for non-acceptance
Quasi-contributors' perspective
16
Gousios, G., Pinzger, M., van Deursen, A. AnExploratoryStudyofthePull-basedSoftwareDevelopmentModel.In ICSE 2014
Zhou, S., Stãnciulescu, Ş., Leßenich, O., Xiong, Y., Wąsowski, A., Kästner, C. IdentifyingFeaturesinForks. In ICSE 2018.

17. "The fix I submitted remained unmerged
until someone else submitted the exact
same fix … the integrators accepted their
(identical) fix and closed mine.”
“when you add a new feature to the project,
your vision can be out of tune with the vision
of the project’s team, and this is natural.”
superseded/duplicatedpull-request(52/335)
[Gousios et al., 2014; Zhou et al., 2018]
“Other pull-requests fixed the same
issues as my pull-requests”
“The project decided that was not a bug they
wanted to provide a fix for”
RQ2. Reasons for non-acceptance
Quasi-contributors' perspective
mismatchbetweendeveloper'sandteam'svision/opinion
(47/335)
17

18. RQ2. Reasons for non-acceptance
Quasi-contributors' perspective
"I did not receive answers"
The process is too onerous, and bureaucratic.”
wasn’t important enough to warrant
merging”
PRnotneeded/notrelevant
(25/335)
bureaucracy
(6/335)
Lackofinterestfromintegrators
(37/335)
Quasi-contributors also offered mea culpa:
→ Not an optimal solution (20)
→ Contributors' lack of experience/commitment (24)
18

19. RQ2. Reasons for non-acceptance
From integrators perspective:
→ PR not needed/not relevant (10/21)
→ guidelines not followed (9/21)
"Trivial PRs that are more
trouble than they are worth"
"proposed changes do not have real value"
"Does not adhere to internal
style or design guidance"
19

20. RQ2. Reasons for non-acceptance
Manualanalysis
263 PRs from
quasi-contributors
Superseded/duplicated
(32/263)
20

21. RQ2. Reasons for non-acceptance
Manualanalysis
263 PRs from
quasi-contributors
Superseded/duplicated
(32/263)
Lackofexperience/
commitment(25/263)
21

22. RQ2. Reasons for non-acceptance
Manualanalysis
263 PRs from
quasi-contributors
Superseded/duplicated
(32/263)
Lackofexperience/
commitment(25/263)
PRnotneeded/notrelevant
(22/263)
22

23. RQ2. Reasons for non-acceptance
Manualanalysis
263 PRs from
quasi-contributors
Superseded/duplicated
(32/263)
Lackofexperience/
commitment(25/263)
PRnotneeded/notrelevant
(22/263)
23
Manualanalysisresults
reverberatethequasi-contributors
answers

24. RQ3. Quasi-contributors' perception
24

25. RQ3. Quasi-contributors' perception
Felt demotivated
Agreed with non-acceptance Yes No
Yes 37 178
No 62 43
25
Disagreement→Demotivation

26. 26

27. 27

28. 28

29. 29

30. 30Disagreement → Demotivation

31. igor.steinmacher@nau.edu
@igorsteinmacher
31

32. Conclusions
● Quasi-contributors are rather common (70% of the actual contributors)
● Different reasons lead to non-acceptance
○ Duplicated/superseded PRs
○ Mismatch between developer's and team's vision
○ Developers' fault
● Non-acceptance may incur in demotivation (⅓ felt demotivated)
● Results can be useful to OSS maintainers, newcomers, and Educators
32

33. RQ1. How common?
33

34. RQ1. How common?
Pull-requests by quasi-contributors are more
discussed
→ in line with Tsay et al. (2014) - more discussed
pull-requests are less likely to be accepted
Tsay, J.; Dabbishm L.; Herbsleb, J. Influenceofsocialandtechnicalfactorsfor
evaluatingcontributioninGitHub. In: ICSE 2014. 356–366. 34

35. RQ1. How common?
Pull-requests by quasi-contributors are more
discussed
→ in line with Tsay et al. (2014) - more discussed
pull-requests are less likely to be accepted
Quasi-contributors' pull-requests tend to be
smaller
Tsay, J.; Dabbishm L.; Herbsleb, J. Influenceofsocialandtechnicalfactorsfor
evaluatingcontributioninGitHub. In: ICSE 2014. 356–366. 35