Re: XP and Pair Programming

On Mon, 22 Aug 2005 11:43:53 -0400, Christopher Barber
<cbarber@xxxxxxxx> wrote:

>Nick Malik [Microsoft] wrote:
>> I've tried it. I like it. The code was not particularly difficult.
>> However, it was developed quicker and with fewer defects because of the
>> pair.
>>
>> Two people stay focused and tuned better than one. IMHO.
>
>I have no doubt that you can produce better software w/ two heads instead of
>one. However, it is not at all clear that two people working a pair are twice
>as productive as one person, which is what it would take to break even.

The research seems to suggest that there is no loss of productivity.
(See Pair Programming Illuminated, by Laurie Williams)
http://www.amazon.com/exec/obidos/tg/detail/-/0201745763/

Anecdotal evidence also supports this result. See:
www.pairprogramming.com


>I
>doubt it. I think you are better off doing it only rarely and relying on
>reviews and frequent programmer interaction the rest of the time.

Reviews are very costly if done correctly. Reviewing a module that
took 5 hours to write should require 5 hours. If you have two or
three people doing the review, you have a very high overhead.

Some people do reviews by passing out 20 pages of code to a dozen
people for a 1 hour review. Perhaps this 20 pages of code require 10
hours to write. Perhaps each reviewer spends 1 hour looking at the
code, and then participates in a 1 hour review session. So review
time is 24 man hours, and does not achieve much depth.

I think its better to pair often, than to pair infrequently. I don't
think 100% pairing is wise though. There are tasks for which pairing
is a waste.


-----
Robert C. Martin (Uncle Bob) | email: unclebob@xxxxxxxxxxxxxxxx
Object Mentor Inc. | blog: www.butunclebob.com
The Agile Transition Experts | web: www.objectmentor.com
800-338-6716


"The aim of science is not to open the door to infinite wisdom,
but to set a limit to infinite error."
-- Bertolt Brecht, Life of Galileo
.

Relevant Pages

  • Re: XP and Pair Programming
    ... > The research seems to suggest that there is no loss of productivity. ... > (See Pair Programming Illuminated, ... >>reviews and frequent programmer interaction the rest of the time. ... > "The aim of science is not to open the door to infinite wisdom, ...
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  • Re: how many bugs do you find and correct during TDD?
    ... Azimov claimed that he never wrote outlines or rough drafts. ... reviews. ... "The aim of science is not to open the door to infinite wisdom, ...
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