Re: 1.5: Discuss link characteristics?

At 17:13 9/2/97 -0800, Jon Bosak wrote:
> I also persist in the belief
>that presentation and behavior are at root the same thing, but the
>list above has persuaded me for the moment that it's more useful to
>talk about all of this under the heading of behavior rather than
>presentation.

They are different. Presentation is concerned with how people recognize that
there is behaviour associated with the text: do they prefer underlined text,
a different colour, an in-line icon, a marginal note. These things are
controllable through user preference, and are therefore overridable at
client side. Colour-blind users must be able to use icons, whereas text only
viewers must be able to replace icons by some textual indication of the
possibility of action.

Behaviour is not up to the user, it is up to the author. It is the
author/server that has to control what happens when the link is selected by
the user. Except in rare cases the user should not be able to change the
action that selecting a link causes.This is why you must separate
presentation from behaviour.

>A. Link display
>
>   How termini are presented to the user.
>
>   - Possibly conditioned on history
>
>   - Possibly including (e.g.) menus to display alternative link
>     target labels ("explainers"), termini represented as animated
>     figures, etc. as well as the usual underlining, etc.

I like this terminology (except for the termini - how the hell do I present
Gard du Nord or Waterloo to users?)

>B. Link traversal
>
>   What happens when a link is traversed.
>
>   - Effects when traversed: opening/closing windows, scrolling,
>     displaying data from termini in various ways (including the
>     automatic transclusion of data without user action)
>
>   - Testing, authenticating, and logging user context information
>
>   - Running programs

This would be better called Link Action. Traversal is not something
non-rocket scientists understand. What most users understand by clicking on
a hotspot is that some action should take place. This is what the
behavioural side of the equation covers.

----
Martin Bryan, The SGML Centre, Churchdown, Glos. GL3 2PU, UK 
Phone/Fax: +44 1452 714029   WWW home page: http://www.u-net.com/~sgml/

Received on Monday, 10 February 1997 04:15:29 UTC