For example, I'm learning geography using the spaced repetition method. I have some program which asks me questions like, "In which country Melbourne is located?", and I have to recall the country (assuming I've studied the material and at least once seen Melbourne on the map). This program also gives me two possible hints when I can't recall the answer:
- If I choose "obvious hint" it says "kangaroo", which for me is a straight giveaway for "Australia".
- If I choose "vague hint" it says "hell". After thinking a while, I may come up with this: "There's the Devil in Hell. There's an animal called Tasmanian Devil, which lives on the island Tasmania, which is near the Australia."
The idea in both cases is to not show the answer right away when I can't recall it, but rather force me (more or less) to try recalling it once again, but now with some additional information.
- Do obvious hints help memorization at all? As you saw, the hint "Australia" is as good as just showing me the answer, but maybe it helps building association in my memory which helps recalling the answer later.
- Do vague hints help more? I assume yes, since they trigger some associations in my memory, but I have no proofs.
Of course, the "obviousness" of a hint is very subjective, but the idea behind it should be clear: "obvious" hints are just one or two associations away from answers, while "vague" ones form longer association chains.
EDIT: There is a related question with an answer which mentions elaborative rehearsal and depth of processing, but I'm not sure if those processes are involved here, since hints are mostly related to an answer ("Kangaroos live in Australia"), not a question ("kangaroos" and "Melbourne" are not associated in my memories, neither do "hell" and "Melbourne").