The general rule is that you can look at any card you have put face down. For example, you can look which cards are stored on your Native Village mat, or what cards are in your Haven, Gear, Archive, etc.
Note that only you can do this, your opponent will just see how many cards there are. So Research is just the same as all those other cards I mentioned above.
Note that Cargo Ship exlicitely puts the card face up on it, so both you and opponent can see the card.