I am looking for a word or words to describe someone who does not give praise or credit to others too readily.
To expand on what I'm looking for, imagine a Martial Arts Master teaching his Student a specific move. The Student gets the very basic concept of the move right but it does not satisfy his Master. The Master will refuse to praise his Students efforts and insists he practices more.
The student practises the move for days with his Master without any praise from his Master until one day he executes the move to his master sanctification. Only then does the Master give praise, and even then the praise is restrained.
Back to reality. I could say the master is very tough and unforgiving with his teaching practices, but the words tough and unforgiving require context for them to have any real meaning. So the word has to be understood on it's own.
Another way to look at it is in terms of facebook Likes. There are people who will like everything their friends post even if it's very insignificant, for example, posting a picture of their cat asleep. On the other hand there are others who would not click like or comment because a picture of cat sleeping is not something they would waste precocious praise on.
I hope I have given you guys any idea of what I am looking for and that a word exist in the English language. If it doesn't then who do I have to speak to to the invent one