At Endeca Discover I had an great conversation with Daniel Tunkelang about his idea that, with respect to guided navigation, we should distinguish between clarify and refine. First, we must clarify the meaning or context. Are we in the right ballpark regarding the searcher's intent? Clarify is all about disambiguation.
Then, we're ready to refine or narrow. Exactly what type of widget do you want? Refine is about increasing specificity. In Is Search Broken? Daniel hints at how we might cut through facets to clarify by leveraging guided summarization.
It's a subtle distinction, but from a designer's perspective, I think it's a valuable way to frame the search process. Clarify, then refine. What do you think?