Some essay test questions are meant to gauge critical thinking. Generalize is one of those terms. When teachers ask you to generalize, they want to see you move from the particular to the general or from the concrete to the abstract.
Writing tip: If you haven't already noted some specific details elsewhere in the test, you'll find it easier to generalize if you start with some details and work your way to a higher level of abstraction.
Specific advice for OT students: Often you are asked to generalize from a theory to a particular person
Substitute key words: draw conclusions