Hypertext
A hypertext (IPA: ˈhaɪ̯pɐˌtɛkst, 
; word formation from Ancient Greek ὑπέρ hyper-, German 'over, above, beyond ...' and Latin texere 'to weave, braid') is a text with a net-like, dynamic structure in which the usual order (linear sequentiality) of static printed publications is technically broken.
It differs from the typical book in that it is not written to be read from beginning to end in the published order. It is written in markup languages that contain hyperlinks, i.e. cross-references to remote text passages or other documents on the network, in addition to design instructions that are not visible to the reader. The most common markup language for Internet documents is Hypertext Markup Language (HTML), which is ubiquitous in the present. A hypertext can be described informatically as a network of hypertext nodes connected by hyperlink edges.
The concept goes back to Vannevar Bush's MEMEX from 1945. The term was coined by Ted Nelson in 1965. The invention of hypertext is culturally and historically closely linked to the encyclopedic idea and the idea of the universal library, and was practically intended to contribute to the discoverability of published research results and the development of better typewriters. The World Wide Web Consortium (W3C) provides the authoritative definition.
Early hypertext editing system at Brown University, 1969. Ted Nelson was involved in its development.
Definition
The definition attempt of the World Wide Web Consortium (W3C) can be assumed as authoritative:
- Hypertext is text that is not constrained to be linear.
- Hypertext is text that contains links to other text.
- HyperMedia is a hypertext that can also contain graphics, videos or sounds (not constrained to be text).
- Hypertext and HyperMedia are concepts, not products.
Types of hypertext systems
In 1987 Jeffrey Conklin systematically examined the properties of 18 hypertext systems and formed four system classes based on typical use cases:
- macro-literary systems that facilitate the handling of large online libraries and serve as a platform for all relevant work steps such as publishing, reading, collaborating and critiquing.
- Heuristic tools (problem exploration) that can be used to transform the initial unstructured ideation phase of a work process into design generation, problem solving, programming or design.
- Browsing systems, which are intended primarily for low-threshold use in teaching, for reference or in public places.
- General hypertext technology intended primarily for experimental purposes.
Properties
Hypertext encodes complex information with comparatively little redundancy compared to linear information representations. Freedom from redundancy saves memory and transmission bandwidth and simplifies the maintenance and updating of content, because a centrally stored value only needs to be changed once to be displayed in all places linked to the value.
The associative structure of a hypertext seems to be more similar to the way human thinking works than purely linear texts. In this context, the pedagogue Rolf Schulmeister refers to the "cognitive plausibility hypothesis".
