I'll open with a firm conviction of mine: there is no fold. Web pages
don't fold. Newspapers fold. Common browser window sizes make for
interesting statistics, but I'd never recommend designing for just
one. There, that's out of the way.
My real question is this: when people in the web design business talk
about items being "below the fold," and the web page in question uses
a #link to skip to the bottom of the page, where the majority of the
site's navigation lives (example: http://powazek.com/), does that
content count as being below the fold? Technically, the visitor
didn't scroll to get to it, and neither did the page reload. In all
of the usability research I've read, this technique is never
mentioned, but things like <a href="#content">Back to top</a> are as
old as the web itself.
Does anybody know if researchers like Jakob Nielsen just never
encounter this sort of thing when they have hundreds of test subjects
using thousands of web pages, or is this behavior simply ignored when