Hypermedia describes a non-linear form of media, the main characteristic of which is hypermediality , i.e. the networking of information nodes with the help of hyperlinks . Hypermedia can be made up of all types and forms of media, the best known variant being hypertext . Hypermedia is often mistakenly equated or confused with multimedia .
The term was first used in 1965 by Ted Nelson . However, the idea of networked media is much older. Without mentioning the term hypermedia itself, Vannevar Bush described the underlying idea in the article As We May Think as early as 1945 for the first time in a technical framework that is still used today.
Hypermedia is based on the linkage of nodes (engl. Nodes ); these nodes can contain different media. While the hypertext only refers to the change between book text, footnotes and glossary, with hypermedia systems texts (in the narrower sense of the word as a sequence of sentences ) with data in a database, graphics (static images), videos (moving images) and sound ( Noise, speech and music events). A non-linear link is created. Hypermedia enables a special form of knowledge generation and representation. It can be understood as a sub-area of e-learning .
Many authors use the terms hypertext and hypermedia synonymously ( Jakob Nielsen 1995 and Rainer Kuhlen 1997). The expanded understanding of " text " from semiotics also indicates the legitimacy of this equation. However, u. a. disregarded the different time characteristics of the different forms of media. Furthermore, this point of view is opposed to the just as much discussed multimedia aspect.
The largest hyper medium currently in existence is the World Wide Web .
As the most important design principle for REST architectures, according to Fielding , Hypermedia as the Engine of Application State (HATEOAS) is based on hypermedia for the loosely binding of various components ( e.g. client and server). The non-linearity and networking described above for media such as text and video also applies here to applications (apps) that dynamically aggregate their functionality via hypermedia from distributed services. The special aspect for the development is based on the fact that the application relies on a generic understanding of hypermedia, consumes / interprets it and reacts to constantly changing interfaces. The architecture components are thus decoupled from one another and do not have to be statically written down and documented, as is the case with SOAP ( WSDL ) or CORBA ( IDL ) , for example .
Problems with multimedia hypertext
A central problem of multimedia hypertext obtained by integrating by the time dimension (ie at the time of creating the hypertext not exactly known) asynchronous (Film / Animation / Video and sound / speech / music) and dynamic elements.
Ordinary text can, for example, be used as a named starting point for triggering the showing of a video film; However, this solution is often viewed as not very hypermedia and inadequate. An alternative approach was developed at the MIT Media Lab for the Elastic Charles project; a small, moving image ( micon [ moving icon ], English for "moving iconogram") serves as the starting point for a hypermedia link.
Another problem of synchronous hypermedia elements with a time dimension is the addressing of a specific point in time of the element (possible using jump labels) or the creation of a link within a moving image or sound sequence. Purely tone-based hypertext systems are then also conceivable.
Application areas of hypermedia systems
Hypermedia concepts enable a multitude of possible applications:
- Technical documentation in the form of manuals
- Tools for the collection and representation of knowledge
- Teaching / learning materials
- Information / information system
- CSCW computer-aided cooperative work
- Computer-aided design and computer-aided engineering
Well-known hypermedia systems
- Rainer Kuhlen : Hypertext in: Buder, Rehfeld, Seeger, Strauch (eds.): Basics of practical information and documentation, Munich a. a .: 1997
- Jakubetz, Christian: Crossmedia. UVK, Konstanz 2008 ISBN 978-3-86764-044-2
- Jakob Nielsen : Multimedia, Hypertext and Internet. Basics and practice of electronic publishing . Braunschweig / Wiesbaden 1996 (German edition of Multimedia and Hypertext. The Internet and Beyond , 1995)
- George P. Landow: Hypertext 3.0. Critical Theory and New Media in an Era of Globalization. 3. Edition. Johns Hopkins Univ. Press, Baltimore Md 2005. ISBN 0-8018-8257-5
- Rolf Schumeister: "Basics of hypermedia learning systems: theory - didactics - design." Bonn; Paris: Addison-Wesley, 1996 ISBN 3-89319-923-3
- Fickert, Thomas: "Multimedia Learning: Basics – Concepts – Technologies." Deutscher Universitäts-Verlag GmbH, Wiesbaden 1992 ISBN 3-8244-2036-8
- http://portal.acm.org/citation.cfm?id=806036 Complex information processing: a file structure for the complex, the changing and the indeterminate
- Roy Thomas Fielding: REST APIs must be hypertext-driven. September 20, 2008, accessed on April 7, 2013 (recommendations for designing REST interfaces with HATEOAS).