Another interesting piece of the theory of knowledge as a philosophical enterprise involves depends about whether the reasons for a person's beliefs are the result of evidence that is internal to the mind/brain (internalism) or a matter of reliable cognitive processes that connect up to the world in the right way (externalism). So conceived, evidentalism is a form of internalism while reliablism is a form of externalism.
The Stanford Encyclopedia of Philosophy's entry on epistemology (located here) has a great illustration of the difference between internalism and externalism. Suppose you have two thinking things, Billie and Billie*. Billie is a person walking around in the world, writing on his blog, thinking about philosophy, teaching, and so on. Billie*, on the other hand, is a Brain-In-a-Vat (BIV), only thinking that he's a person walking around the world, writing on his blog, thinking about philosophy, teaching, and so on. According to the internalist, even though we can admit that Billie* is deceived or mistaken in his beliefs insofar as they connect up to the world, since Billie and Billie* both have the same mental states, and since they have a set of consistent beliefs or are being properly sensorily manipulated, or manipulated by their nerve endings in a certain way so as to think they are experience the states they're in, they both have good reasons for believing what they believe. The externalist, on the other hand, would say that since the correct cognitive processes do not link up with Billie*, he's both deceived and doesn't really have good reasons for his beliefs because the beliefs ought to come about by being correctly connected to the world..
So okay, let's think about this debate for a bit, and the debate between internalists and externalists. In my view, and given the situation we are in, we are all situated beings incapable of getting outside of our own skins. But insofar as we can make use of higher cognitive faculties and do science and try to understand the world using our normal cognitive faculties, we are doing our best to get out of our own skins (I'm paraphrasing a Chomsky quote I once heard there). Since 'knowledge' is an honorific word and not some essential word that designates a chunk of reality, we are right to call knowledge certain canons of evidence we have accumulated and spread, all of which are ultimately internal. No matter what we do in our study, we are all basically methodological internalists. It could be the case that the world isn't even out there (although we suspect that it is). But should it be discovered that what we think is out there isn't out there, we would have to modify our view and be skeptics about the external world. In the absence of good reasons for doubt, we just proceed according to investigations.
But also it might be worth mentioning that even if we suppose we discovered that we were all BIVs, this too could give grounds for doubt because it could be that that is just some cognitive illusions, and so instead we could be quarks that have acquired self-consciousness, or still some other entity. This gives us reason to believe that what we are really doing is a kind of Cartesian project, where we can call knowledge anything that have given an explanatory account of, call good reasons those which have held up time and time again using our senses, the most sophisticated tools we have out our disposal, experiments, cognitive processes, and so on. From a certain point of view, then, our point of view, it would always and everywhere be impossible to be externalists, since this view from nowhere is unachievable.