Visual Layout

When designing hypertext screens (visual aspect of nodes mostly) a number of formatting and organizational issues arise. Some are a function of authoring principles; others are determined by computer capabilities.

Spacing of lines is important because the long line length on conventional computer screens, combined with the low resolution of the screens, makes reading a lot harder than reading from paper. Until recently it was not possible to specify line spacing for WWW-browsers. (Cascading Style Sheets have made this possible.)

The main principle of screen design is that displays should not be "cluttered" and contain too much information. Higher screen resolution and larger screens allow more information.

The use of scrolling windows removes the restriction of cutting the information into pieces of a fixed size. (This limitation in for instance KMS made converting the CACM issue on Hypertext to KMS difficult.) Scrolling puts a burden on the reader. While vertical scrolling may make it difficult to keep track of where you are when you scroll up or down, horizontal scrolling, especially with text, makes it extremely difficult to keep track of where you are.

When fonts can be changed and windows can be resized it becomes harder for the author to design the visual layout of a screen. Some of the nodes in this course only look "right" when using a window that is wide enough to display wide images. Also, the images contain text, which only looks right if the surrounding text is displayed in the same font. Most hypertext systems do not resize figures to make them fit the window.

When the user can create multiple windows on the screen at the same time, the issue arises as to what should be displayed in different windows. Should the user be allowed to see the same node in multiple windows in order to compare different portions? Should the user be allowed to specify that when following a link the destination node appears in an adjacent window instead of replacing the current document? Leaving such a choice up to the user (like with WWW-browsers that open a new window or not depending on the mouse button used when clicking on a link anchor) usually means that the author can no longer control how many windows a user may have open simultaneously. Unfortunately given the popularity of the Web authors may not have the option of not authoring for systems with this property.