As a computer scientist/programmer, there are three numbers, 0, 1, and infinity. If you're going to index your errors by the natural numbers, and you've got Type 1 Errors and Type 2 Errors, my next question is what a Type 3 Error is, and you know what my next question after that is.

Otherwise, please take this wisdom from programmers, who deal with this sort of thing all the time, and use an enumeration, in this case, {False Positive, False Negative} will do just fine.

What are some synonyms to Kahneman's System 1 and System 2 then? Because Type 1 and 2 errors seem to be completely equivalent to false and positive negatives. I think Kahneman motivates his decision to introduce the terms System 1 and 2 quite well in his book, and I don't know of any direct counterparts.

Ahaha, I agree so much the the Kahneman jibe. How could someone so smart pick names so f*cking dumb?!

When you are designing an hypothesis test the term positive and negative are not so clear. For example you can test that mean weight of bags is greater than 5.0 kg or smaller than 5.0 kg, both test are different, and some times you can accept both greater and smaller than 5.0 kg. The philosophy of hypotesis test is not as clear as a standard tests for pregnancy. In other terms,in some cases the H0 hypothesis is symmetric (>= versus =<) and is not clear what a positive result should be, you have to state clearly what is the H0 hypothesis. In a pregnancy test everyone agree than H0 is that you are not pregnant, that is in my HO the semantic difference between Type 1 error and false negative.

Of course false-positives can also be bad. To use your example "you then spend $10,000 prepping for the baby, but it never comes, what a waste!"