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Pair Programming
Myth Busters
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What is Pair Programming?
Two programmers work as a pair
together on one workstation.
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Nuts & Bolts
Driver
Navigator
Roles
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Nuts & Bolts
Pair
Rotation
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But…
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“If a task takes 1 hour, it
takes 2 hours in pair programming.”
Myth #1
myth \ˈmith\
noun
an idea or story that is believed by many people
but that is not true.
Merrium-Webster ®
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Pairing doubles the time?
“That would be true if the hardest part
of programming was typing.”
Martin Fowler
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Pairing doubles the time?
“Pairs spend 15% more time than individuals. However,
resulting code has about 15% fewer defects.”
Cockburn, Alistair; Williams, Laurie (2000).
"The Costs and Benefits of Pair Programming" (PDF)
.
Proceedings of the First International Conference on Extreme
Programming and Flexible Processes in Software Engineering
(XP2000)
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Pairing doubles the time?
—Cockburn, Alistair; Williams, Laurie (XP2000)
“Pairs typically
consider more
design alternatives.”
“… arrives at simpler, more
maintainable designs.”
“They also catch
design defects
early.”
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Pairing doubles the time?
trust
work is fun
everyone is
a star!
continuous
review
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“If a task takes 1 hour, it
takes 2 hours in pair programming.”
Myth #1
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“This fix is needed urgently; it is
better done alone to save time.”
Myth #2
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Is pairing slower?
time
if
30%
extra
even if
100%
extra!
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pairing == slower bug fixing?
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“This fix is needed urgently.”
Pairing not for emergency?
confidence
minimize
regression
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“This fix is needed urgently; it is
better done alone to save time.”
Myth #2
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“It works well only with right partner.”
Myth #3
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Pairing with People
Is there a right partner?
openness
verbal
communication
brainstorming
feedback
negotiation
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One more thing…
You’ll know
yourself
better
You’ll know
your team
better!
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Myth #3
“It works well only with right partner.”
partner.”
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“It is good only for complex tasks; there is
no need to pair program on simple tasks.”
Myth #4
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Simple task
Pairing not for simple tasks?
Repetitive?
Quick?
pairing
motivates
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“If I'm writing boring repetitive code it's
usually a sign that I've missed an
important abstraction, Pairing will help
you find that abstraction.”
- Martin Fowler
Pairing not for simple tasks?
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Ending notes…
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The Book
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Dedicated to…
Bhattu Hari Krishna
my first pair programmer
- Ragu
Ragunathan Pattabiraman
my worst pair programmer
- Rajesh
&
Bill Watterson
creator of
Calvin and Hobbes
the finest of pair programmers
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Thank you
Ragunathan Pattabiraman
Rajesh Yanuganti