in reply to Unit Tests and Creative Tension
Beck suggests this in Test Driven Development as being the right thing to do when you're the only person working on a project. He points out that it doesn't work with a team for some fairly obvious reasons. However, in an XP environment (at least) the odds are that you'll start the next day paired with someone else, so you get your creative tension that way; even if you do pair with the same person, you at least have someone to bounce things off.
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