MSR 2015

1. An Empirical Study of the Copy and
Paste Behavior during Development
Tarek M. Ahmed
1
Weiyi Shang Ahmed E. Hassan

2. Copy & Paste leads to clones
//Code fragment
Copy
2
//Code fragment
Paste

3. //Code fragment
Copy
//Code fragment
Paste
Copy & Paste leads to clones
3
Large number of code clones

4. Clone detection tools detect
C&P after it is performed
Source Code
Clone
Detection
4
Code Clones

5. There exists no large scale C&P
study on developers
5
Controlled ExperimentSmall number Experienced only

6. Larger scale study exists on
regular users
• Regular computer users
• Non-Software development tasks
A large scale C&P study is needed for software
development tasks
6

7. Eclipse Usage Data Collector
(UDC) enables a large scale
C&P study
20 Months
7
>1 Millions Users

8. How to detect C&P in Eclipse
UDC
User ID What Kind … Description
104526 Executed Command org.eclipse.ui.edit.copy
User performs Copy
8

9. How to detect C&P in Eclipse
UDC
User ID What Kind … Description
104526 Executed Command org.eclipse.ui.edit.copy
104526 Executed Command org.eclipse.ui.edit.paste
User performs Paste
9

10. Our study focuses on users
who frequently and actively use
Eclipse
Create
Development
Sessions
10
Find Active
Sessions
Find Frequent
Users

11. 20 Months
11
4 Million C&P20,000 Users

12. Uncovering the C&P behavior
of IDE users
12

13. Average number of C&P per hour is
different from recent studies
13
2.73 16
Our finding
Previous
finding
#Commands > Average #Commands
+ 1 Standard deviation
#Commands > Average #Commands
+ 2 Standard deviation
Heavy
Editing
Sessions
V. Heavy
Editing
Sessions
11.39 13.18

14. Do IDE users follow the
same C&P patterns as
regular users?
How do IDE users copy
and paste code across
different file formats?
14

15. Do IDE users follow the
same C&P patterns as
regular users?
How do IDE users copy
and paste code across
different file formats?
15

16. 16
Copy
//Code fragment
Paste
//Code fragment
Inside the same file Between different files
Copy
//Code fragment
//Code fragment
Paste

17. 17
Copy
//Code fragment
Paste
//Code fragment
Inside the same file Between different files
Copy
//Code fragment
//Code fragment
Paste
IDE users often C&P within the same file

18. IDE users perform consecutive
C&P
A
18
Repeat
Copy
CCopy
B
Paste
D Paste

19. IDE users perform consecutive
C&P
A
B
C
19
Distribution
Copy
Paste
Paste

20. IDE users perform consecutive
C&P
A B C
20
Relay
Copy
CopyPaste
Paste

21. IDE users often perform relay
on C&P
A
C
B
D
A
B
C
A B C
21
Repeat Distribution
Relay

22. C&P behavior of IDE users is
different from regular users
IDE Users
 Higher Within
 Higher Relay
 Lower Distribution
Regular Users
 Higher Between
 Lower Relay
 Higher Distribution
Eclipse IDE requires tailored C&P support tools that differ
from regular users’ C&P tools
22

23. Do IDE users follow the
same C&P patterns as
regular users?
How do IDE users copy
and paste code across
different file formats?
23
There are major differences
between C&P behavior of Eclipse
IDE users and C&P behavior of
regular users.

24. Do IDE users follow the
same C&P patterns as
regular users?
How do IDE users copy
and paste code across
different file formats?
24
There are major differences
between C&P behavior of Eclipse
IDE users and C&P behavior of
regular users.
There exists large number of C&P
between editors, hence, clone
detection techniques would
consider detect clones across
different languages.

25. Summary
25

26. 26