In this article, we assume partner opened 1NT (15-17).
As responder, with a five-card (or longer) MAJOR, I recommend always transferring. See this article.
But, with a five-card (or longer) minor, it is a completely different ballgame.
With the major, transferring allows you to play on the two-level. But, with a minor, a transfer puts you on the three level. Why would you want to play in 3