Re: 1.5: Discuss link characteristics?
I'm still trying to figure out the right categories within which to
think about formatting, presentation, and behavior. In section 1.5,
the current draft says:
4. link formatting: Links commonly differ in how they should be
presented. This includes both how the user is informed that a link
is present (such as highlighting, perhaps conditioned on history
or other factors as in typical Web browsers), but also how the
other termini are presented, such as having their title, summary,
or explainer shown, or even being completely followed and
presented inline with no user action required for traversal.
5. link behavior: Links may have a wide variety of effects when
traversed, such as opening, closing, or scrolling windows or
panes; displaying the data from various termini in various ways;
testing, authenticating, or logging user and context information;
executing various programs. Ideally, link behavior should be
determined by a semantic specification based on link types,
pointer roles, user circumstances, and other factors; just as
element formatting is determined by a stylesheet based on element
type, context, and other factors. It is recognized that there is
significant overlap between the areas of link formatting and link
The list of things that need to be specified is very helpful, but I
don't think that the division between formatting and behavior is quite
right yet. For one thing, it seems clear to me that inline
presentation without user action belongs to behavior rather than
It's very difficult to get these things sorted out, but I persist in
the belief that it's necessary to do so. 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
I think that part of the problem is an unexamined tendency (in which I
participate) to make the basic cut between that which is visible to
the user and that which is not. While this distinction is important,
perhaps it should not be the one with the highest logical priority.
This leads me to suggest the following.
Instead of the two categories "4. link formatting" and "5. link
behavior", which I don't think are separable, make a single item
number 4, "link behavior", and then distinguish between two categories
of behavior, link display and link traversal, as follows:
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.
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
Note that in this taxonomy, the distinction between visible and
invisible and the distinction between user-initiated and automatic are
secondary to the distinction between display behavior and traversal