[timr]

That's a matter of debate. Some people think that the problem is search limited, others think that the current models are bad. In my opinion, the bulk of the evidence supports the latter conclusion.

Backchannel me, and I'll be happy to provide you with references to the papers I wrote/helped write. Most of them aren't open access, unfortunately.

[aswanson]

Will do. And thanks for the info, you may have spared me a decade or so of wasted effort.