"Bayer, Samuel" <sam(at)mitre(dot)org> writes:
> One concrete question, I suppose, is: the classic TF/IDF search strategy relies on inverse document frequency, which looks across the corpus. I can't tell whether that corpus-wide frequency information is taken into account in either ranking function.
The documentation is pretty clear that they don't, they just consider each
document in isolation. Building a structure that would allow more-global
info to be taken into account is an interesting project that nobody's
tackled.
regards, tom lane