HYPERTEXT
Hypertext most often refers to
text on a computer
that will lead the user to other, related information on demand. Hypertext
represents a
relatively recent
innovation to user interfaces, which
overcomes some of the limitations of written text. Rather than remaining static
like
traditional text, hypertext makes
possible a dynamic organization of information through links and connections
(called hyperlinks).
Hypertext can
be designed to perform
various tasks; for instance when a user "clicks" on it or
"hovers" over it, a bubble with a word definition may appear,
a web page on a
related subject may load, a video clip may run, or an application may open.
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The prefix hyper-
(comes from the Greek prefix "υπερ-"
and means "over" or "beyond") signifies the overcoming of
the old linear constraints
of written text. The term
"hypertext" is often used where the term hypermedia
might seem appropriate. In 1992 Ted
Nelson - who coined both
terms in 1965 -
wrote:
By now the word
"hypertext" has become generally accepted for branching and
responding text, but the corresponding word "hypermedia,"
meaning complexes of branching
and responding graphics, movies and sound - as well as text - is much less
used. Instead they use the strange
term "interactive
multimedia" - four syllables longer, and not expressing the idea that it
extends hypertext. - Nelson, Literary
Machines 1992
Hypertext documents can
either be static (prepared and stored in advance) or dynamic (continually
changing in response to user input).
Static hypertext can be
used to cross-reference collections of data in documents, software applications, or
books on CDs.
A well-constructed
system can also incorporate other user-interface conventions, such as menus and
command lines.
Hypertext can develop
very complex and dynamic systems of linking and cross-referencing. The most
famous implementation
of hypertext is the World
Wide Web.
Recorders of information
have long looked for ways to categorize and compile it. Early on, experiments
existed with various methods for arranging
layers of annotations
around a document. The most famous example of this is the Talmud.
Various other reference works (for example
dictionaries, encyclopedias,
etc.) also developed a precursor to hypertext,
consisting of setting certain words in small capital letters, indicating
that an entry existed for
that term within the same reference work. Sometimes the term would be preceded
by a pointing hand dingbat,
☞like this, or an arrow, ➧like this.
Later, several scholars
entered the scene who believed that humanity
was drowning in information, causing foolish
decisions and duplicating efforts
among scientists.
These scholars proposed or developed proto-hypertext systems predating
electronic computer technology. For example, in the
early 20th century,
two visionaries attacked the cross-referencing problem through proposals based
on labor-intensive,
brute force methods.
Paul
Otlet proposed a proto-hypertext concept
based on his monographic principle, in which all documents would be decomposed
down to
unique phrases stored on index
cards. In the 1930s, H.G.
Wells proposed the creation of a World
Brain.
Michael
Buckland summarized the very advanced pre-World War II development
of microfilm based on rapid retrieval devices, specifically
the microfilm based workstation
proposed by Leonard
Townsend in 1938 and the microfilm and photoelectronic
based selector, patented
by Emmanuel
Goldberg in 1931.[1]
Buckland concluded: "The pre-war information retrieval specialists of
continental Europe, the 'documentalists,'
largely disregarded
by post-war information retrieval specialists, had ideas that were considerably
more advanced than is now generally realized."
But, like the manual
index card model, these microfilm devices provided rapid retrieval based on
pre-coded indices and classification schemes
published as part of the
microfilm record without including the link model which distinguishes the
modern concept of hypertext from content
or category based information retrieval.
All major histories
of what we now call hypertext start in 1945, when Vannevar Bush wrote an article in The Atlantic Monthly
called
"As
We May Think," about a futuristic device he called a Memex.
He described the device as an electromechanical desk linked to an extensive
archive of microfilms,
able to display books,
writings,
or any document from a library. The Memex would also be able to create 'trails' of linked
and branching sets of
pages, combining pages from the published microfilm library with personal
annotations or additions captured on a microfilm
recorder. Bush's vision was
based on extensions of 1945 technology - microfilm recording and retrieval in
this case. However, the modern story
of hypertext starts with
the Memex because "As We May Think"
directly influenced and inspired the two American men generally credited
with the invention of
hypertext, Ted
Nelson and Douglas Engelbart.
Ted
Nelson coined the words "hypertext" and
"hypermedia" in 1965 and worked with Andries van Dam to develop the Hypertext Editing System
in 1968 at Brown
University. Engelbart had begun working on
his NLS system in 1962 at Stanford Research Institute,
although delays in obtaining
funding, personnel,
and equipment meant that its key features were not completed until 1968. In
December of that year, Engelbart demonstrated
a hypertext interface
to the public for the first time, in what has come to be known as "The Mother of All Demos".
Funding for NLS slowed
after 1974. Influential work in the following decade included NoteCards at Xerox
PARC and ZOG at Carnegie
Mellon.
ZOG started in 1972 as an artificial intelligence
research project under the supervision of Allen
Newell, and pioneered the "frame" or "card"
model of hypertext.
ZOG was deployed in 1982 on the U.S.S. Carl Vinson and later
commercialized as Knowledge Management System.
Two other influential hypertext projects from
the early 1980s were Ben Shneiderman's The Interactive
Encyclopedia System (TIES)
at the University of Maryland
(1983) and Intermedia
at Brown University (1984).
The first hypermedia
application was the Aspen Movie Map in 1977. In
1980, Tim Berners-Lee created ENQUIRE,
an early hypertext database system
somewhat like a wiki. The
early 1980s also saw a number of experimental
hypertext and hypermedia programs, many of
whose features and
terminology were later integrated into the
Web. Guide was the first hypertext
system for personal computers.
In August 1987, Apple
Computer released HyperCard for the Macintosh
line at the MacWorld convention.
Its impact, combined with interest
in Peter J. Brown's GUIDE
(marketed by OWL and released earlier that year) and Brown University's Intermedia, led to broad interest in and
enthusiasm for hypertext and new
media. The first ACM Hypertext academic conference took place
in November 1987, in Chapel Hill NC.
Meanwhile Nelson, who
had been working on and advocating his Xanadu system for over two decades, along with
the commercial success
of HyperCard, stirred Autodesk
to invest in his revolutionary ideas. The project continued at Autodesk for
four years, but no product was released.
In the late 1980s,
Berners-Lee, then a scientist at CERN, invented the World
Wide Web to meet the demand for automatic information-sharing
among scientists
working in different universities and institutes all over the world. In 1992, Lynx was born as an early
Internet web browser.
Its ability to provide hypertext links within
documents that could reach into documents anywhere on the Internet began the
creation of
the web on the Internet.
Early in 1993, the National Center for
Supercomputing Applications (NCSA) at the University of Illinois
released the first version of their
Mosaic web browser to supplement the two existing web
browsers: one that ran only on NeXTSTEP
and one that was only minimally user-friendly.
Because it could display
and link graphics as well as text, Mosaic quickly became the replacement for
Lynx. Mosaic ran in the X Window System
environment, which was then popular
in the research community, and offered usable window-based interactions. It
allowed images[2]
as well as
text to anchor hypertext
links. It also incorporated other protocols intended to coordinate information
across the Internet, such as Gopher.[3]
After the release of web
browsers for both the PC and Macintosh
environments, traffic on the World Wide Web quickly exploded from only 500
known web servers in 1993 to
over 10,000 in 1994. Thus, all earlier hypertext systems were overshadowed by
the success of the web, even though
it originally lacked
many features of those earlier systems, such as an easy way to edit what you
were reading, typed links, backlinks,
transclusion,
and source
tracking.
In 1995, Ward
Cunningham made the first wiki available, making the web more hypertextual by adding easy editing, and (within a single
wiki)
backlinks and limited source
tracking. It also added the innovation of making it possible to link to pages that
did not yet exist.
Wiki developers continue
to implement novel features as well as those developed or imagined in the early
explorations of hypertext
but not included in the
original web.
©WIKIPEDIA.
URL: http://en.wikipedia.org/wiki/Hypertext (visited 03/12/08)
Academic year 2008/2009
© a.r.e.a./Dr.Vicente Forés López
© Gema Martí López
gemarlo@alumni.uv.es
Universitat de València Press
Página
creada: 03/10/08 actualizada: 08/11/08.