PairProgramming
Apracticalguide
11/5/2016 – Giuseppe Sorrentino

Objective
Present pair programming as agile practice
◦ Definition and Advantages
◦ Roles and Duties
Provide clear and slick guidelines to improve pair programming within the pod
◦ Restarting, Planning and Action
◦ Tips and Tricks
PAIR PROGRAMMING – A PRACTICAL GUIDE 2

Definition
PAIR PROGRAMMING – A PRACTICAL GUIDE 3
“Pair programming isa dialog between two people trying to…understand how to program better.”4
Itintegrateswell intoanagileenvironment because itallows:1
• to produce better software by continuous inspection ofcode;
• to foster face-to-face communication.

Evidence 1
PAIR PROGRAMMING – A PRACTICAL GUIDE 4
Two programmers together vs. Twoprogrammers alone
Two programmers together work more thantwice asfastand thinkof more thantwice asmanysolution toa
problem astwo working together.
Five experienced programmers individually vs. five couple of experienced programmers
Groups completed the task40% more quicklyandeffectivelyby producing better algotithmsandcode inless
time.

Roles

PAIR PROGRAMMING – A PRACTICAL GUIDE 6
Duties
◦ Active role on the keyboard/mouse
◦ Focuses on the code at hand:
◦ Syntax
◦ Semantics
◦ Algorithm
◦ Verbalise his thoughts
◦ Concentrates to pass the next test
Driver
◦ No active role on the keyboard mouse
◦ Continually reviews the work
◦ Catches incidental mistakes
◦ Anything which needs further verification
◦ Overall code design
◦ Focuses on a strategic level
◦ Checks the consistency of the code being written with existent code
◦ Tracks if other changes are needed in different area of the code
base
◦ Suggest design and algorithm enhancements
Navigator
They switch often (from 10 to 20 minutes) only by swiping the keyboard

ActivityTime
7
Findthequestions

PAIR PROGRAMMING – A PRACTICAL GUIDE 8
Example
◦ In this case is better a multiple if structure or a switch
case?
◦ Which the most explicative name for this variable?
Driver
◦ How will this fit with the rest of the code?
◦ Will this implementation require changes elsewhere?
◦ Could we design this program better?
Navigator

Restarting, Planning and Action2
PAIR PROGRAMMING – A PRACTICAL GUIDE 9
Research recognized three main phases:
• Restarting: when a couple is stuck
• Planning: when a couple is deciding on their next actions
• Action: when a couple is actively performing a task
Guideline to drive these phases are in the notes.
https://www.youtube.com/watch?v=ONnYCT_LJio

Tips and Tricks1,2,3,4
PAIR PROGRAMMING – A PRACTICAL GUIDE 10
• Kill any distractor (browser, chats, notifications, etc.)
• Use an editor both are familiar with
• A good pairing time is four hours
• Do not pair to execute systematic and repetitive tasks
• Avoid to form always the same couples
• Check that your partner is active
• Healthy debate and avoid excess ego
• Use an appropriate workspace layout (switch keyboard)

ActivityTime
11
Plusanddelta

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• Code quality
• Speed
• Learning
• Familiarization
Pair Programming Balance
Conclusion

References
PAIR PROGRAMMING – A PRACTICAL GUIDE 13
1. L. A. Williams and R. R. Kessler, “All I really need to know about pair programming I learned in kindergarten,”
Communications of the ACM, vol. 43, no. 5, pp. 108–114, 2000.
2. M. Zarb, J. Hughes, and J. Richards, “Evaluating industry-inspired pair programming communication guidelines
with undergraduate students,” in Proceedings of the 45th ACM technical symposium on Computer science
education, 2014, pp. 361–366.
3. L. Williams, R. R. Kessler, W. Cunningham, and R. Jeffries, “Strengthening the case for pair programming,” IEEE
software, vol. 17, no. 4, pp. 19–25, 2000.
4. M. Kircher, P. Jain, A. Corsaro, and D. Levine, “Distributed extreme programming,” Extreme Programming and
Flexible Processes in Software Engineering, Italy, pp. 66–71, 2001.

Thankyou!