How does epistemology compare or contrast with postmodernism?
The previous post is quite right. Epistemology does not compete or challenge postmodernism, which has a distinct belief on how individuals come to know what they know. The postmodern epistemological stance is one that is rooted in fragmentation. For the postmodern, individuals can come to know what they know through their own experience. There is little in way of transcendence that helps to provide this understanding nor can this understanding seek to be universally transcendent in its own right. In this light, the postmodern notion of epistemology is one that can be appropriated by anyone, yet cannot be seen as totalizing for everyone.
As I understand it, this is not really a compare or contrast sort of a thing. Epistemology is, of course, the study of how (or if) knowledge is possible. Postmodernism is a set of ideas about the world. As such, they are not really things you can contrast.
Instead, I would say that postmodernism has a specific take on epistemology. Specifically, I think that postmodernists kind of think that you cannot really ever know anything for sure. Therefore, I would say that you have to say that postmodernists have an epistemological belief -- one that says true knowledge is impossible.