Text is the most widely used and flexible means of presenting information on screen and conveying ideas. The designer should not necessarily try to replace textual elements with pictures or sound, but should consider how to present text in an acceptable way and supplementing it with other media. For a public system, where the eyesight of its users will vary considerably, a clear reasonably large font should be used. Users will also be put off by the display of large amounts of text and will find it hard to scan. To present tourist information about a hotel, for example, information should be presented concisely under clear separate headings such as location, services available, prices, contact details etc.
Guidelines Conventional upper and lower case text should be used for the presentation since reading is faster compared to all upper case text.
All upper case can be used if a text item has to attract attention as in warnings and alarm messages.
The length of text lines should be no longer than around 60 characters to achieve optimal reading speed.
Only one third of a display should be filled with text.
Proportional spacing and ragged lines also minimises unpleasant visual effects.
12 point text is the practical minimum to adopt for PC based screens, with the use of 14 point or higher for screens of poorer resolution than a normal desktop PC
If the users do not have their vision corrected for VDU use e.g. the public. It is recommended that text of 16 point is preferred if it is to be usable by people with visual impairments.
Sentences should be short and concise and not be split over pages.
Technical expressions should be used only where the user is familiar with them from their daily routine, and should be made as understandable as possible e.g. "You are now contacting with Paul Andrews" rather than "Connection to Multipoint Control Unit".
The number of abbreviations used in an application should be kept to a minimum. They should be used only when the abbreviation is routinely used and where the shorter words lead to a reduction of information density.
Abbreviations should be used in a consistent way throughout an entire multimedia application.
An explanation of the abbreviations used in the system should be readily available to the user through on-line help facilities or at least through written documentation.
Copyright EMMUS 1999.