There is something going on with the learning rate from appraising creatures while hunting I think. At 38 appraisal on a new character i'm able to appraise Endrus Serpents and other creatures i'm hunting, but there is no learning from it regardless if its done with quick or careful.

Appraisal in combat seems pretty low overall but it does work and I was able to get all my ranks for the most part on my moon mage by just doing it in combat. So I'm certain it does work eventually, I just assume its some sort of bug that you can appraise them and get the messages but get no experience at lower ranks.

"An' I'm learnin' 'ere in London what the ten-year soldier tells; If you've 'eard the East a-callin', you won't never 'eed naught else. No! you won't 'eed nothin' else"