Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!sri-spam!ames!ucbcad!ucbvax!iris.UUCP!tms
From: tms@iris.UUCP.UUCP
Newsgroups: comp.society.futures
Subject: Re: Hypertext Usenet
Message-ID: <8711121344.AA11654@iris.brown.edu>
Date: Thu, 12-Nov-87 08:44:05 EST
Article-I.D.: iris.8711121344.AA11654
Posted: Thu Nov 12 08:44:05 1987
Date-Received: Sat, 14-Nov-87 14:53:42 EST
References: <8711072049.AA23357@bu-cs.BU.EDU>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: IRIS, Brown Univ, Providence, RI
Lines: 65

In article <> you write:
>If we really want to have linking at the sub-article level,
>don't we need to specify the region covered by a link, rather
>than assuming that a link reference pertains to the last 
>word/phrase/concept before the reference?  There's a lot of
>ambiguity there; imagine a paragraph expressing an idea which
>ends in an example, followed by a reference.  You really need
>some way to know whether the referenced article discusses the
>idea of the paragraph, or just describes the example.
>
I'm replying by e-mail rather than posting to the net because our net
connection is a diode pointing at me.  You may know that we at IRIS have been
working with a hypermedia (including hypertext) system for some time now.

We agree entirely with your above notion.  The paradigm that we have
implemented is that links begin and end on a "block".  A block can be thought
of as a persistent selection.  It is defined using a point-press-drag-release
gesture, as well as the normal range of click/double-click stuff.  In
Intermedia, you first create a selection, then perform a "start-link" menu
pick.  Sometime later you perform a "complete-link".

Once created, links are indicated by marker icons laid onto the document
image.  These markers may be selected and "followed" (a menu pick), or they
may be double-clicked, implying a select-and-follow operation.

Lets hope that unix land does, in fact, actually design and think about this
stuff before jumping into an implementation.  Maybe folks will even read some
of the papers that have been published since 1967 (now THERES a novel thought).
There are lots of subtleties that really jump out and grab you if you're not
VERY careful.  I hope the unix hackers explore some of this before making the
rest of us suffer through their learning curve.

Thanks,
Tom Stambaugh.

ps:

I've seen a few postings on this subject that propose the insertion of stuff
in the text to indicate links.  This is a profoundly BAD idea, particularly
in this context, because it forces every link to be shared by every user.

Our research indicates that a much better design principle is to treat the
collection of links (we call such a collection a "web") as an external data
structure layered on top of a read-only document.  For text such as this,
blocks can be indicated by an offset and extent.  Now, each user can layer
his/her own links onto a passively read news article.  The user doesn't need
write access and the article isn't cluttered up with other people's links.  If
the author of a posting wants to also post a suggested web for folks to share,
that can be posted and handled separately; as I user, I can take it if I want
or skip it if I want.  Given that the news tools like find and expire use the
touch date to decide when to throw away a posting, you can imagine the havoc
that would result from a linking scheme that requires each new link to cause
a write to the original article!  The result would probably be to preclude
readers from creating their own links, thus blowing away the primary reason
to support links in the first place.

Charlie Evett, from IRIS, has published a paper describing the scheme we use
at IRIS for tracking blocks in text documents.  I think that was distributed
at this weekend's hypertext conference in North Carolina.  Charlie is
responsible for a good bit of the graphics machinery of Intermedia, and in
particular came up with an elegant solution to several implementation issues
that result from doing this stuff with text.  I highly recommend his paper.

If you think this ps is of interest to the net, feel free to post it for me.
Someday I'll get our net support working.