Okay, that's good enough for me :) To speak plainly, the problem is that with duck-typing in computer science, it's trivial to determine whether or not an obje

Okay, that's good enough for me :) To speak plainly, the problem is that with duck-typing in computer science, it's trivial to determine whether or not an object has a given method. With regards to people, it's very difficult to reliably assess whether or not someone has a given personality trait, and it's even more difficult to know whether or not associating various personality traits together is beneficial. Different measures yield different results, both with regards to personality type and with regards to interactions between types.