Pair Programming

Overview

• Two people working together on the same code, at the same workstation.
• One person is the "Driver", they are doing the typing.
• The other person is the "Navigator", they are watching the driver, and thinking about things on a different or higher level since they aren't distracted by typing.
• Much more info in links below

Benefits

• There are many benefits to pair programming, many are mentioned in links below, such as
  • Higher quality code (best ideas from two people make it into the code)
  • More discipline (people keep each other honest - e.g. "Aren't you going to write a test for that???")
  • Spread skills and knowledge across team and company quicker, deeper, and more efficiently
  • Prevent silos of knowledge and risk because "only one person know this code"
  • Keep people from goofing off - pairs work all day unless they are taking breaks - no surfing the web, zoning out to your headphones, etc...
  • Better office communication and team cohesiveness - people are listening and overhearing other pairs and learning/helping as appropriate, not lost in their headphones.

Important Things to Remember

• Communicate!
• The "driver" should be talking constantly, explaining what they are doing and why. A silent pair is not a good pair.
• Don't be afraid to stop the pair and ask questions. There's no dumb question, novice questions are good. Just by asking "why in the heck are you doing THAT?", a "novice" programmer can make a "master" programmer think twice, and prevent them from going down a rathole, saving hours, days, maybe even weeks!
• Have fun!
• Take breaks often, and at the same time as your pair!

Tips

Consider doing TDD with Ping Pong Pairing: http://c2.com/cgi/wiki?PairProgrammingPingPongPattern

• One person writes a failing test. Say "Ping" and switch drivers
• Other person makes the test pass, then writes the next failing test. Say "Pong" and switch drivers
• Repeat...

Remote Pairing

There's a separate page on Remote Pairing

Links

• http://guide.agilealliance.org/guide/pairing.html
• http://www.extremeprogramming.org/rules/pair.html
• http://en.wikipedia.org/wiki/Pair_programming
• http://c2.com/cgi/wiki?PairProgramming
• http://www.wikihow.com/Pair-Program