I’d like to develop a finite, coherent set of attributes that determine how much information to put on a page (a virtual, scrolling page that is) and that size of that page. It seems like a small enough scope to get scientific about it.

The bookseller site analysis I did was informative (long pages seem to be OK in some contexts, density of text and links are something to look closer at). Some other relevant issues might be:

1. Cooper, who says navigation isn’t fun, so make fewer pages with more to do (my personal take here is that interaction design is harder than your usual layout-content-and-links design, so only use interaction design if you can nail the interaction, otherwise keep it simple
2. factor in page weight of course (which in turn factors in download speed)
3. factor in the time it takes for elements to display (since stuff loading in over time is actually what people experience)