Since the better screens have a resolution of about 100 dpi while the average laser printer has a resolution of 300 or 600 dpi, it is clear that what appears on the screen cannot be an exact replica of what will appear on paper (unless one settles for lousy printouts which are no more than screendumps). This difference can be partly compensated by using anti-aliasing, a technique to give the impression of a higher resolution screen.
Some document processing systems come close to being WYSIWYG (MS-Word and Framemaker are some of the more popular ones), but this makes the small but noticeable differences between what appears on the screen and what appears on the paper more irritable. Early work of prof. De Bra has concentrated on providing an interface for document processing that is sometimes called WYSIAWYG (What You See Is Almost What You Get) or even just What You See Looks Real Neat. WYSIAWYG is the best you can get for high quality document processing systems, since exact positioning of characters is impossible and depends on the printer (or screen) resolution. The same document with the same layout cannot look perfect on a 300 dpi, 600 dpi and a 1200 dpi printer. Each printer requires different character positioning, leading to different line breaks and possibly also different page breaks. An interface showing the kind of printout you will get (showing fonts, section numbers, ragged or straight margins, etc.) is close enough to be a real improvement over batch-oriented processing, while it is sufficiently different from real WYSIWYG to not be confused with a real WYSIWYG interface. (it does not show accurate line breaks, hyphenation, page breaks, inline equations, graphics, etc.)
The fact that true WYSIWYG systems cannot place characters in the best possible position is not the only problem. Another disadvantage of true WYSIWYG systems over the more advanced batch oriented systems is that their user-friendly and thus relatively simple interface does not offer the same possibilities as the batch oriented systems. What You See Is also All You Get.
The user-interface used for this course is a good example of what a What You See Looks Real Neat interface offers. (Although this interface is not an interface for document processing.)