• Use graphical fonts to catch a viewer’s. attention because of their size and unusual shape, even if they may be less legible than normal fonts (Nes, 1986).
• Be consistent in addressing textual cues and signals to the learner (Faiola, 1989). Consistency in typographic. signals and cueing can establish and convey a very clear visual message to the viewers that they are now reading a certain subject or section of instructional content.
• Use both upper and lower case letters (Apple Computer Inc., 1989; Faiola & DeBloois,1988). The legibility of text with letters in mixed case, i.e., with capitals only used for indicating the first letter of a sentence, a name, etc., is higher than for letters in upper case only (van Nes, 1986). All upper case characters should be used only occasionally, and for the purposes of emphasis (Strauss, 1991).
• Use high contrast between letters and background to improve legibility and readability (Isaacs, 1987; Pastoor, 1990; Reynolds, 1979; Rivlin, Lewis, & Davies- Copper, 1990).
• Left-justify text, but do not right-justify it (Garner, 1990). Limit text to approximately 65 characters per line, or a maximum of 8-10 words per line (Galitz, 1989, Garner, 1990). Increase the spacing between lines for long lines of text (Garner, 1990; Hartley, 199,0). ,