> Fix all other variables. That's literally impossible to do in a straight one to one comparison. If nothing else, you have different people working at each on

> Fix all other variables. That's literally impossible to do in a straight one to one comparison. If nothing else, you have different people working at each one. A broader study might get enough data to make meaningful comparisons, but I think strict TDD is too rare to get more than a few samples. It's a tough problem. I think you'd have to set up a completely artificial environment if you truly want to measure the relative efficiency of TDD.