Current printers and displays do not draw letters using a continuous motion. A raster is used, and (circular) dots are "painted" black. In order to give the impression of being drawn in a fluent motion the dots must be small and very close together. The following figures shows the letter A at different resolutions, making the difference clear:
With paper, and at a normal reading distance (of about 1 foot or 30 cm) a resolution of at least 300 dots per inch (around 120 dots per cm) is needed to hide the fact that letters are composed from individual dots. (At closer range, or for some graphic images, the dots can still be detected at resolutions of up to about 600 dpi, depending on the granularity of the paper).
Screen resolution today varies between 50 and 100 dpi, too low to compare to paper output. Improving the resolution to about 300 dpi is not likely to happen in the near future. On screens that are able to display different greyscales however it is possible to use dots at different grey levels to give the impression of a higher resolution display. This technique is known as anti-aliasing and is similar to a technique used in printers, called resolution enhancement. (In the latter technique smaller dots are used instead of grey dots.) The leftmost letter A looks best because it was generated using different grey levels. Unfortunately most display systems (X-Windows, MS-Windows, Macintosh) do not use anti-aliasing.
Research (by Wright and Lickorish [WL83], and Gould and Grischkowsky [GG84]) has shown that reading (and comprehending) information from a screen takes about 30% longer than reading the same information on paper. Wilkinson and Robinshaw (1987) found that people get tired more easily when reading from computer screens than when reading from paper. Using a high resolution screen (91 dpi) and anti-aliased fonts, Gould et al. [GA87] found no significant difference in reading speed between that screen and paper.
The above research suggests that in order to make reading this course text as comfortable as reading printed material the windowing system (Windows'95, X-Windows, or whichever you are using) would need to support anti-aliasing. Unfortunately, this is not likely the case and it is beyond the control of the author of the text.