Text presentation
Evidence suggests that the most commonly used fonts tend to be equally legible at the 10-, 12-, and 14-point size. Comparing four sans serif fonts (Arial, Comic Sans MS, Tahoma, and Verdana) and four serif fonts (Courier New, Georgia, Century Schoolbook, Times New Roman) at a resolution of 1024 x 768 revealed no difference in effective reading (font accuracy/speed of reading) between font types (Bernard, Lida, Riley, Hackler, & Janzen, 2002). This finding is supported by Bernard, Mills, Frank, and McKown (2001), which did not find significant differences as well.
This is not to say there are no objective differences between the fonts. In fact, there is some evidence that suggest that some serif fonts promote better comprehension than some sans serif fonts. For example, a study by Boyarski, Neuwirth, Forlizzi, and Regli (1998) found small but significantly higher levels of comprehension for the Georgia font over the sans serif font Verdana by people reading on a computer screen. However, it is really too early to draw any definitive conclusions from this. Studies need to further examine the effect of different fonts on reading comprehension.
Significant differences in reading time were found in that Times New Roman and Arial were read faster than Courier New, Century Schoolbook, and Georgia. Fonts at the 10-point size were read more slowly than fonts at the 12-point size (see Figure 1). The average difference between the fastest and slowest read font was 99.4 seconds.
Figure 1. Reading time in seconds (longer bars indicated longer reading times)