Jakob Nielsen's Multimedia and Hypertext and others

Multimedia and Hypertext —The Internet and Beyound

http://www.useit.com/jakob/mmhtbook.html

Technically

a. Definition of Hypertext and Hypermedia:

The simplest way to define hypertext is to contrast it with traditional text like this book. All traditional text, whether in printed form or in computer files, is sequential meaning that there is a single linear sequence defining the order in which the text is to be read.
Hypertext is nonsequential; there is no single order that determines the sequence in which the text is to be read.
The traditional definition of the term "hypertext" implies that it is a system for dealing with plain text. Since many of the current systems actually also include the possibility for working with graphics and various other media, some people prefer using the term hypermedia, to stress the multimedia aspects of their system. Personally, I would like to keep using the traditional term "hypertext" for all systems since there does not seem to be any reason to reserve a special term for text-only systems. Therefore I tend to use the two terms hypertext and hypermedia interchangeably with a preference to sticking to hypertext.

b. History of Hypertext:

1945 Vannevar Bush proposes Memex
1965 Ted Nelson coins the word "hypertext"
1967 The Hypertext Editing System and FRESS, Brown University,
Andy van Dam
1968 Doug Engelbart demo of NLS system at FJCC
1975 ZOG (now KMS): CMU
1978 Aspen Movie Map, first hypermedia videodisk
Andy Lippman, MIT Architecture Machine Group
1984 Filevision from Telos; limited hypermedia
database widely available for the Macintosh
1985 Symbolics Document Examiner, Janet Walker
1985 Intermedia, Brown University, Norman Meyrowitz
1986 OWL introduces Guide, first widely available hypertext
1987 Apple introduces HyperCard, Bill Atkinson
1987 Hyperertext'87 Workshop, North Carolina
1991 World Wide Web at CERN becomes first global hypertext,
Tim Berners-Lee
1992 New York Times Book Review cover story on hypertext fiction
1993 Mosaic anointed Internet killer app, National Center for
Supercomputing Applications
1993 A Hard Day's Night becomes the first full-length feature film
in hypermedia
1993 Hypermedia encyclopedias sell more copies than print encyclopedias

c. The Architecture of Hypertext Systems

Presentation level: user interface
Hypertext Abstract Machine (HAM) level: nodes and links
Database level: storage, shared data, and network access

The Database Level:
The database level is at the bottom of the three-level model and deals with all the traditional issues of information storage that do not really have anything specifically to do with hypertext.
Ultimately it will be the database level's responsibility to enforce the access controls which may be defined at the upper levels of the architecture.
As far as the database level is concerned, the hypertext nodes and links are just data objects with no particular meaning.

The Hypertext Abstract Machine (HAM) Level:
The HAM is the best candidate for standardization of import-export formats for hypertexts, since the database level has to be heavily machine dependent in its storage format and the user interface level is highly different from one hypertext system to the next.

The User Interface Level
The user interface deals with the presentation of the information in the HAM, including such issues as what commands should be made available to the user, how to show nodes and links, and whether to include overview diagrams or not.

Usability

Usability is traditionally associated with five usability attributes:

Easy to learn: The user can quickly get some work done with the system.
Efficient to use: Once the user has learned the system, a high level of productivity is possible.
Easy to remember: The casual userig able to return to using the system after some period of
not having used it, without having to learn everything all over.
Few errors: Users do not make maty errors during the use of the system, or if they do make
errors they can easily recover from them. Also, no catastrophic errors must occur.
Pleasant to use: Users are subjectively satisfied by using the system; they like it.

3. Applications

a. Susan Hockey. The Reality of Electronic Editions. Voice, text, hypertext : emerging practices in textual studies / edited by Raimonda Modiano, Leroy F. Searle, and Peter Shillingsburg.
Much hype currently surrounds discussions on hypertext, electronic textuality, theory of electronic text, and related topics, especially in rela­tion to the preparation of electronic editions and archives. Leading textual scholars have embraced the idea of electronic texts and textuality and have speculated at length about this new medium, both in print and on the Internet.1 In practical terms, however, we are very much farther behind. Few implementations exist, and most of these are, in my view, poorly designed and weak in functionality. They tend to have too much dependence on the Hyper Text Markup Language (HTML) and native web technology and to incorporate too many multimedia gimmicks.
Prescriptive markup indicates the functions that are to be carried out on the text. Prescriptive markup restricts the functionality of the electronic text because the text, once marked up in this fashion, can really be used only for the functions pre­ scribed in the markup. By far the most widely used form of prescrip­tive markup is that created by word-processing programs.
Descriptive markup is much more powerful and flexible. The con­cept behind descriptive markup is very simple: instead of indicating what the computer is to do with a given component of the text, descrip­tive markup merely says what that component is. Standard Generalized Markup Language (SGML) and the Extensible Markup Language (XML) make it possible to create a set of encoding tags that directly correspond to the components of the text.8 An SGML / XML-based data model can avoid many of the simplification problems associated with HTML and can easily be extended if additional features have to be encoded. The principles of SGML can be summa­rized briefly as follows:
1. An SGML / XML-encoded text is a plain ASCII file, which can be read independently of any specific word-processing program. XML sup­ports Unicode as well. Thus the same text can be used for many differ­ent purposes and will outlast the computer on which it was created.
2. SGML / XML itself is a syntax or framework for defining markup languages, and the set of specific markup tags for one particular project is called an SGML/XML application.
3. These markup tags, and the relationships among them, must be defined in a document type definition (DTD) in SGML and XML (and possibly in a schema in XML), which gives a formal specification of the document's structure.
4. Almost anything, from a complete text down to the detailed inter­pretation of one part of a word (for example, the "ur" portion of the term "ur-text), can be encoded in SGML / XML. It is up to the designer of a DTD to determine what is important and what should be encoded— a process known as document analysis.

An electronic edition should:
(1) maintain current standards of scholarly editorial excellence;
(2) facilitate changes in scholarly editorial practice;
(3) allow postpublication enhancements of editions;
(4) allow multiple forms of publication; and
(5)conform to relevant standards for electronic text, images, and other material.

b. Kahn, P. (1989b). Linking together books: Experiments in adapting published material into hypertext. Hypermedia 1, 2,111-145.

Describes the conversion of a set of books on Chinese poetry into Intermedia format, giving plenty of screen shots. One interesting illustration is an overview diagram of the translators of the poet Tu Fu, which are ordered in two dimensions: Chronologically on the y-axis and according to the translator's emphasis on sinology or poetry on the x-axis. The author distinguishes between objective links (those present in the text being converted such as explicit literature references) and subjective links (those added because the converter or other hypertext user sees a connection between two items).

“The links in a body of literature can be viewed as connecting two classes of associations: objective and subjective. Objective associations are thosethat derive from the structure of the texts themselves, the text as data.Subjective associations are those that derive from an interpretive understanding of the material.
Objective associations can be used to generate links between items in the data. In a body of literature, objective associations are to be found in the structural and linguistic properties of the text, and the properties of the author associated with the text. Many current printed reference works, which are already structured along these lines, contain the necessary information to create such objective hypertexts.
Subjective associations are to be found in the same text, but the associations are located in the ideas which a scholar sees as represented by the text. Common examples in literature include commentaries on, or indications of, influences or similarities among authors or works.”