can I force non-serif fonts?

[mactbone]

http://www.cs.indiana.edu/classes/a106/about.fonts.html

One thing to keep in mind when choosing to serif or not to serif: studies have shown that serifed fonts are generally easier to read than sans-serif fonts. The effect is most pronounced at smaller font sizes, so body text is typically in a serifed font

http://www.hqlogos.com/logo-design-infobase-item.asp?id=99

The philosophy behind this is that the serif fonts guide the reader into an understanding of the piece as a whole. Words are not to be objectified by breaking them down into soldiered rows of individual letters. They are meant to be digested holistically, and serifs are the connectors that slow the reader down just long enough for greater comprehension.

Studies show that reading comprehension is greater when serif fonts are used. However, studies with children may be more indicative of the truth of the matter: children in the early reading stages showed no benefit either way. People are better at reading what they are used to reading.

http://hubel.sfasu.edu/courseinfo/SL99/typography.html

In summary, the following data were discussed (better refers to an increase in reading speed or legibility):

for normal luminance and normal size, serif is better than sans serif
for normal luminance and smaller size, sans serif is better than serif
for low luminance, sans serif is better than serif.
serifs may cause a crowding effect
for smaller size, PW may cause a crowding effect
FW serif is better than PW serif.
for medium to large size, PW is better than FW
for smaller size, FW is better than PW.
sans serif has a lower acuity level than serif
PW must be 15% larger than FW to share equal acuity levels

Serif is more aesthetically pleasing if nothing else from all accounts. I find it surprising that people with low vision should read sans-serif fonts - apparently the serifs clutter more than they help.

[Apocalypse]

The first link is most likely just talking out of their ass and doesn't cite anything.

I find it hilarious that the second study cites Michael Bernard, while Bernard states there is no significant difference between types of fonts.

His research even goes against your third link.

Reading Time

In examining the reading time for each font combination irrespective of their accuracy, a marginal type/size font interaction was found [F(1, 26) = 3.39, p < .08]. As shown in Figure 1, post hoc analysis revealed that the 12-point serif fonts were significantly slower to read than the 14-point serif fonts (p < .004) or the 14-point sans serif fonts
(p < .05). No other interactions were significant.

http://psychology.wichita.edu/surl/usabilitynews/3W/fontSR.htm

While it did say serif is faster, it also said the difference was not significant.