@cybmole The document linked
Code:
http://www.surl.org/usabilitynews/72/columns.asp
deals with online web pages, undergraduates and comprehension.
Ebooks are quite different, I WAS an undergraduate (and post-graduate) but that was nearly fifty years ago and now I use a medium sized text for reading. Ebooks, mine anyway, don't allow for proportional spacing or hyphenation so you end up with silly spacing. I suggest you reread the article at the link again and be less selective about what you quote.