I'm skeptical of that. So far things like POS tagging have not demonstrated any benefit in academic information retrieval results, to my knowledge. Granted this

I'm skeptical of that. So far things like POS tagging have not demonstrated any benefit in academic information retrieval results, to my knowledge. Granted this is an "absence of evidence" argument, and maybe that shouldn't be taken too seriously. Academic IR is a funny business, because nobody who wants to change the world or is deeply intellectually curious goes into it. They go work for Google/Yahoo/MS, who can tell them in a day all the things they'd discover ten years for now. But still, all the obvious ways to use POS tagging for IR have been tried, and don't work. POS is only just marginally useful in machine translation at the moment! This isn't that surprising when you think about it. What POS tags provide is a small clue about grammatical structure. So you're either setting off down that path and trying to understand a sentence as a tree, or you're going to understand a sentence as a sequence of words. Syntax is hard, and most word-word dependencies are between adjacent words. There's a local maximum at "just use the words", and POS tags don't take you far enough to get past it for many tasks.