Every now and then I witness people getting this one wrong after partner opens 1NT. It concerns how to handle 5332-hands with a major suit and scattered strength. Here's a piece of advice you can take to the bank. Don't try to use your judgement, just transfer or bid your major (depending on your NT-methods).
You can't get 100% right, but it's so overwhelming, you can stop reading. In one recent international match (names withheld;), our contestants were dealt:
... and faced a 14-16 1NT-opening across the table. This seemed like an occasion to forego this advice and both passed. After the defence collected 5 diamonds and 2 spades with 9 tricks cold in a heart contract, another deal went to the evidence room. This time partner held:
It's impossible to know what is right on any given hand, therefore consistency is needed. Always opt for the major.