Code reading is an activity frequently performed by developers. Before modifying code, developers have to read it, especially if it was authored by others. Several studies have been carried out to find insights related to code readability. However, they were mostly conducted on single (static) code snippets, i.e., they did not take into account the ever-changing nature of software. In a preliminary study, we observe that refactoring operations performed by developers to improve several non-functional aspects of open-source software systems often result in improved code readability. Motivated by such results, in this thesis, we studied code readability in the context of software evolution. Especially, we aimed at understanding: (i) to what extent software developers are interested in code readability; (ii) how code readability evolves in complex software systems; (iii) the influence of developers’ personal characteristics on the evolution of code readability. First, we observed that the large majority of the developers we surveyed reported that they consider readability as an important aspect of the source code. Then, by mining several software repositories we observed that readability rarely changes in software evolution. Therefore, files created unreadable rarely become readable, and vice versa. Finally, we noticed that some personal characteristics of developers have an impact on code readability. In particular, developers’ orienting network (related to their attention) positively correlates with code readability.

1. ON THE EVOLUTION OF
CODE READABILITY
VALENTINA PIANTADOSI
valentina.piantadosi@unimol.it

2. Studying the Evolution of
Code Readability
during the life-cycle
of software
GOAL
1

3. 2
readable unreadable
change
DOES MAINTENANCE
DETERIORATE THE READABILITY
OF THE CODE?

4. WHERE DOES THE
IDEA OF STUDYING
THE EVOLUTION
OF READABILITY
ORIGINATES?
3

5. 4
WHY DEVELOPERS REFACTOR SOURCE CODE:
A MINING-BASED STUDY
J. PANTIUCHINA, F. ZAMPETTI, S. SCALABRINO, V. PIANTADOSI, R.OLIVETO, G. BAVOTA, M. DI PENTA
ACM TRANSACATION ON SOFTWARE ENGINEERING AND METHODOLOGY (TOSEM)

6. ~85%
refactoring
operations are
performed to
improve
code readability
5

7. 6
IS THERE A REAL
IMPACT ON CODE
QUALITY MEASURED
IN TERMS OF
READABILITY?

8. readable unreadable
non-existing
other-name
rename
rename
create
create
change
change change
7

9. readable unreadable
non-existing
other-name
rename
rename
create
create
change
change change
Tool designed to work on
single code snapshots
SCALABRINO, S. ET AL.
A COMPREHENSIVE MODEL FOR CODE READABILITY
2017
8

10. readable unreadable
non-existing
other-name
rename
rename
create
create
change
change change
9

11. 10
IS THERE A REAL
IMPACT ON CODE
QUALITY MEASURED
IN TERMS OF
READABILITY?
NO!

12. 11
My code seems to be
unreadable….
I will do refactoring to improve
code readability!
Unreadable code Unreadable code
SCALABRINO’S
METRIC
0.3
REFACTORING
OPERATION
SCALABRINO’S
METRIC
0.4

13. 12
WHAT CAN AFFECT
THE READABILITY OF
SOURCE CODE?

14. 13
WHAT CAN AFFECT
THE READABILITY OF
SOURCE CODE?
MAYBE, COGNITIVE
HUMAN ASPECTS?

15. 14
Why does my code remain
unreadable?
For me, now it is readable!
Unreadable code Unreadable code
SCALABRINO’S
METRIC
0.3
REFACTORING
OPERATION
SCALABRINO’S
METRIC
0.4

16. 15
Why does my code remain
unreadable?
For me, now it is readable!
Bob is right!
Also for me, this code is
readable!
WRONG MENTAL MODEL INFLUENCED MENTAL MODEL

17. 16
Why does my code remain
unreadable?
For me, now it is readable!
WRONG MENTAL MODEL
BY WHAT
COGNITIVE HUMAN
ASPECT WAS
READABILITY
AFFECTED?
ATTENTION?
MEMORY?

18. Alerting
Orienting
Executive control
Working memory
Immediate recall
Attention-related factors
17

19. Alerting
Orienting
Executive control
Working memory
Immediate recall
Attention-related factors
18
Memory-related factors

20. Alerting
Orienting
Executive control
Working memory
Immediate recall
Ability of gaining and
maintaining an alert state
19

21. Alerting
Orienting
Executive control
Working memory
Immediate recall
Ability of selecting information
from sensory input
20

22. Alerting
Orienting
Executive control
Working memory
Immediate recall
Ability of dealing with
conflict among responses
21

23. Alerting
Orienting
Executive control
Working memory
Immediate recall
Ability of recalling information
acquired in the very short term
22

24. Alerting
Orienting
Executive control
Working memory
Immediate recall
Ability of elaborating
problem-solving strategies
23

25. ORIENTING INFLUENCE
CODE READABILITY
24

26. Orienting
25
Code readability

27. 26
HOW THE RESEARCH
COMMUNITY CAN
EXPLOIT THE
RESULTS ACHIEVED?

28. 27
01
Researchers could create a new readability
transition model based on changes instead of
single snapshots would be necessary

29. 28
02
Researchers should investigate if there are
other cognitive human factors that could
influence code readability

30. 29
Researchers should study what personal
characteristics can help developers to
implement quality code
03

31. 30
Researchers could propose to developers
specific training sessions for their
development tasks
04

32. ON THE EVOLUTION OF
CODE READABILITY
AUTHOR
VALENTINA PIANTADOSI
THANK YOU FOR THE ATTENTION!