From Brian Marick:

When I used to watch [Kent] Beck do this, I was sure he was really doing macro design “in his head” and just not talking about it, because you can see the design taking shape, but he never seems to be doing anything directed to the design. So I started trying it. What I experience is that I am never doing anything directed to macro design or architecture: just making small changes, removing duplication, improving the expressiveness of little patches of code. Yet the overall design of the system improves. I swear I’m not doing it.