From: olson@mydual.uucp (Kirtland H. Olson)
Subject: Re: Definition of Hypertext ?
Organization: The Harvard Group, 01451-0667
Date: Fri, 25 Dec 1992 14:39:05 GMT

In article <6761@tuegate.tue.nl> toin@blade.stack.urc.tue.nl (Toin Bloo) writes:
>I know only a little of hypertext, but I need to use a kind of definition
>of it in a report about "electronic script". 
>Can someone post a nice and sound definition of the "idea" of hypertext?
>
>Thanks in advance!
>-- 
>Toin Bloo                      member of: The Young Scientists Eindhoven
>+31 40 622681 (home)                      Frederiklaan 163  5616 NE  Eindhoven
>toin@stack.urc.tue.nl                     The Netherlands, Europe
>                                          (toin%storc@dutentb.et.tudelft.nl)

"By 'hypertext' I mean non-sequential writing." --Theodor H. Nelson

"_Basic_or_chunk_style_hypertext_ offers choices, either as
footnote-markers (like asterisks) or labels at the end of a chunk. 
Whatever you point at then comes to the screen."  

"'As We May Think' (_Atlantic_Monthly_, July, 1945) is most notable for
its clear description of various hypertext techniques--that is linkages
between documents which may be brought rapidly to the screen according
to their linkages. (So what if he [Vannevar Bush] thought they'd be on
microfilm.)"

Quotations from Dream Machines, pp 44-5, copr. 1974, Theodor H. Nelson  

Although Nelson called it non-sequential writing, I find it easier to
understand as multi-sequential writing--there are many orders available
and I may follow one until another seems more attractive.

I've posted the following material before, but see the section
HYPER[whatever]--a structure of linked nodes.  

I think these are the definitions I actually use in thinking about
hypertext and hypermedia.  My internal picture of the structure is a
finite state diagram in which each node represents one state of the
system labelled by the collection of values that uniquely address that
state no matter what the incoming path.  In my mind the nodes are
arranged so that each is adjacent to those whose state labels differ by
exactly one unit in the particular variable.


NODE--the end of a link. 

	Just the end of a link, no notion of content or capability. 
Sort of like an airport--maybe nice, maybe great, maybe just a dirt
strip.  Node names a class of things that occur at the end of links.

LINK--a transition between nodes. 

	Although links have some physical representation for the engine,
to the reader links equal action.  Link names a class of actions that move
the reader in the structure.  I could as well think of this as
'changenode' without distrurbing my picture of the process.  


HYPER[whatever]--a structure of linked nodes.
	
	Often the [whatever] attempts to distinguish node content in
some gross and approximate way.  Hyper[text] may mean text only,
anything that can be shown on a text-only display (including character
graphics) or anything that doesn't move or make noise--except maybe
sound effects or ...  You get the picture.  Similarly full motion video
plus text might be hyper[media] as well as full fidelity audio with
photorealistic slides.  But all these share the concept of a structure
within which one can traverse links to arrive at nodes.  


HYPER[whatever] ENGINE--software to implement the structure on a
			platform.

HYPER[whatever] TOOLS--software to control the engine.

I know the reasoning seems circular (I prefer to think of it as self-consistent)
but this is the most complex structure into which I can fit the systems
I know of.  Any attempt to make more specific definitions gets me in
trouble with one or more hyper[whatever] systems.  For example, HyperRez
does not separate nodes that contain only a list of choices from those
that contain no further choices at all--both are files, addressed in the
same way, equally visible to the reader--they just don't differ.  Other
systems seem to keep those meta-nodes in separate databases, but I reach
them through a link.  Thus I can't fit both into one node class more specific
than "the end of a link."  

Similarly, if I were to say links connect two nodes, the systems that
use AI to alter the links on the fly will not fit.  

-- 
Kirtland H. Olson                     olson%mydual.uucp@alliant.com