Pair programming involves two programmers working together at one computer. One programmer acts as the driver who writes code while the other serves as the navigator who reviews the code as it is written. This approach has benefits like producing higher quality code, faster development times, greater knowledge sharing, and improved teamwork. It works because the pair members provide pressure, reviews, and learning opportunities for each other. Effective pair programming requires an accessible workspace, communication between partners, consistent standards, understanding teammates' strengths, and rotating pair assignments. Some disadvantages are that it requires an even number of developers and can be challenging with skills imbalances or disagreements between partners.

1. PAIR
PROGRAMMING
NAME : JASLEEN
ROLL NO:10509
(GROUP:C1)

2. What is it?
•“Two programmers work side-by-side at
one computer, continuously collaborating
on the same design, algorithm, code, and
test.”
•It allows two people to produce a higher
quality of code than that produced by the
summation of their individual efforts.

3. How it works
• Driver
– Actively implements the program.
– Actually types or writes down
– Explains actions taken
– Participates in brainstorming/planning
• Navigator
– Continuously observes the work of the driver to identify
defects.
– Thinks about the direction of the work.

4. Driver
Navigator

5. Pair Programming
• Driver and Navigator working together
on one task
• Roles changing often
• Collective responsibility for outcome
• Bringing together of multiple
perspectives, experiences and abilities

6. Why Pair ???
• Higher quality code
• Faster cycle time
• Enhanced trust/teamwork
• Knowledge transfer
• Enhanced learning
• More fun

7. Higher Quality Code
• Immediate reviews of all code written
• Multiple perspectives on how code
should work
• People from different areas
(UI/database, development/testing)
working together – no (incorrect)
assumptions
• Each person learns from the other –
increased skills

8. Faster cycle time
• Less temptation/ability to get distracted
on non-work things
• Less rework due to bad assumptions
• Fewer defects slip through, so less
rework for defect repair
• Less interruption for pair
• More communication

9. Enhanced Trust/Teamwork
• People in pairs get to know each other
better than people working solo
• Better understanding of people’s skills
• Shared events = common ground

10. Knowledge Transfer
• Rotation of pairs means lots of
combinations
• Lots of combinations make knowledge
transfer exponential
• Fewer assumptions

11. Enhanced Learning
• Each member of a pair has ongoing
opportunities to learn from their partner

12. More Fun
• Social interactions
• Shared events
• Studies show high numbers of people
trying pair programming prefer it

13. Why Pair Programming Works
• Pair Pressure
• Pair Negotiation
• Pair Courage
• Pair Reviews
• Pair Debugging
• Pair Learning
• Pair Trust

14. Pair Pressure
• Each member doesn’t want to let the
other down
• Improved adherence to procedures and
standards
• Motivation to get a task done in a
session while partner is available

15. Pair Negotiation
• Working together to get the best
solution
• Each pair member has
– Own set of skills, abilities, outlook.
– Shared goal of accomplishing task
• Brainstorming (building on ideas of
others)

16. Pair Courage
• Having a partner agree with a fix or a
solution adds confidence to the solution
• Two people expressing confusion are
more confident to go get the help they
need

17. Pair Reviews
• Members of pairs are immediately
reviewing code as it is written
• Two heads better than one

18. Pair Debugging
• Effective debugging technique is to
explain problem to someone else
• Talking about problem in a pair can
lead to a solution becoming obvious

19. Pair Learning
• No two people are at exact same levels
of knowledge on software development
• Exposure to different approaches

20. Enabling Pair Programming
• Accessible workspace
• Communication
• Standards
• Knowledge of people’s specialties
• Pair rotation
• Group appraisal
• Smaller groups

21. Workspace accessible to both
• Display visible to both people
• Side by side, not one in front of the
other
• Keyboard/mouse available to either
person

22. Expectation of communication
• Ask to drive
• Ask questions
• Explain actions taken

23. Standards
• Standard tools reduce learning curve
time in pairs
• Coding standards assist in both
members following the code being
written and avoid disagreements on
how to write something

24. Knowledge of people’s
specialties
• Know who to pair with to achieve
benefit in a given situation
• If a task overlaps two areas (e.g., UI
and database) pair one person from
each area

25. Pair Rotation
• No given pair of programmers is the
right pair for every situation
• Rotation enables knowledge transfer

26. Disadvantages to Pair
Programming
• Requires even number of developers
• Scheduling
• Experts/Skill Imbalances
• Concentration
• Disagreements
• Overconfidence
• Loss of personal development space
• Not for everyone

27. THANK YOU