At Smalltalk Solutions '98, I went to JeffMcKenna's talk on how to do Smalltalk projects.  He seemed to have a lot of thinking that went along ExtremeProgramming lines, but there were some places where he differed significantly.  Two examples were that he strongly values CodeOwnership and documentation.

At first I wondered how such a wise and respected man could be so wrong about these areas where we differed.  Then I began to think about the forces acting on projects and whether he had different priorities than we have in C3.

It turns out that he has a high priority for reuse, because he's looking enterprise-wide, and we have a low one, because we are focusing on delivery of this one integrated application.

There were some other differences as well, but the reuse one is enough to drive you to produce more documentation, and to need stronger control over changes to classes, since versions have to be compatible, by and large, from one to the next.

What I learned, for the millionth time, was that when there's a difference of opinion on what should be done, it is often (usually?) due to a difference of values, perhaps on a topic that hasn't even been brought up yet. --RonJeffries
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For a long time now, I've made it a point to think very carefully before deciding that someone who's very smart and has lots and lots of practical experience is dead wrong. That includes most of the contributors around here. --AnthonyLander
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It is very interesting to go back and read things that you may well have said and now would no longer say.  Perhaps we all learn as we go. --JeffMcKenna