What defines your keyword matches

I've read the faqs, but looking for a matrix

[bnhall]

Howdy. There seems to be a lot of opinion on where google
looks to determine if you're a keyword "hit" or not. Here's
what I'm reading - is this correct? Can anyone add/subtract
from or confirm/deny this list?

Page Title - Definitely
Meta Description - No?
Meta Keywords - No?
Keyword Density w/in page text - Yes?
Backlink text - Definitely
img alt text - Not sure?
H2s - Definitely?
H1s or H3s - Not sure?
domain name - Maybe?

Thanks.

[agerhart]

Page Title - YES
Meta Description - No
Meta Keywords - No
Keyword Density w/in page text - YES
Backlink text - YES
Outbound link text - YES
Image and Directory Filenames - YES
img alt text - YES
H2s - YES
H1s or H3s - YES
domain name - YES