[xenophanes]

Epistemology explains how learning (aka creating knowledge) happens and what sorts of methods are capable of learning or not, and what sort are more or less effective at learning (aka at getting knowledge). This is useful to actually learning (anything) effectively.

Note again that most work in the field is terrible, so it doesn't actually do this. But the stuff I recommended does.

[stewbrew]

Epistemology is a field of philosophy not psychology.