Thumbs up for faceted searching

David Weinberger posts about NCSU implementation of faceted searching

"Why is this a big deal? Unlike parametric searches that let you enter specifications for your search, a faceted search doesn't simply apply search criteria. Instead, a faceted classification system — in this instance, called a "guided navigation" system by Endeca, the company behind this implementation — the browsable interface changes with every choice so that it never shows you parameters that would result in an empty results list. So, you don't have to keep randomly banging on it and then backing up, trying to find the one book you want, or the one left-threaded, chrome-plated, 15mm, philips-headed, round-capped screw you need as you build the specs for your new aircraft engine. And when it turns out there are no screws exactly like that, you can decide you could do without the chrome-plating, or the philips-headedness, until you get something that works. "