Indeed the more complex and complete you make your rational model, the more tunable weights there are. By just dropping in the right weights, you can get whatev

Indeed the more complex and complete you make your rational model, the more tunable weights there are. By just dropping in the right weights, you can get whatever result you want. Therefore complex models tend to produce worse results in practice than very simple ones. This lesson was brought home for me by https://www.amazon.com/Software-Estimation-Demystifying-Developer-Practices/dp/0735605351 https://www.amazon.com/Software-Estimation-Demystifying-Deve... explaining why the COCOMO model didn't work well in practice as an estimation technique, despite their having collected a lot of good data on what affects schedule. This lesson is one that the EA community broadly seems to ignore.