On: Fonts for web design: a primer

[ugh]

Guidelines one and two have no empirical support. It seems to be the case that choice of font is merely a aesthetic decision.

See:

http://scholar.lib.vt.edu/theses/available/etd-102999-110544... (PDF)

http://www.laurenscharff.com/research/AHNCUR.html

http://sigchi.org/chi95/Electronic/documnts/intpost/tst_bdy....

http://www.surl.org/usabilitynews/22/font.asp

https://eldorado.tu-dortmund.de/dspace/bitstream/2003/24419/... (PDF, German)

http://www.designtagebuch.de/die-gefuehlte-lesbarkeit/ (German)