Hypertext is text that is non-linear in structure and contains references to other text or content through the use of a net structure. These references are usually implemented via hyperlinks. This form of text is created in markup languages like HTML (Hypertext Markup Language) or XML (Extensible Markup Language) which contain explicit instructions for the visual formatting of text as well as hyperlinks. Clicking on such a link allows users to access content directly, resulting in an interactive reading experience.
Before the invention of the World Wide Web (WWW), text was primarily presented in linear structures. But this linearity had a decisive disadvantage: coherent texts had to be read page by page one after the other. While this was not too much of an issue with short texts, it was strongly criticized for texts of several hundred pages. This is because such a text consists of a large number of coherent parts located in different places. In a conventional text, these are barely linked and the contexts can only be recognized after reading the entire document.
To solve this problem, an American computer scientist called Ted Nelson started to develop a non-linear knowledge database that was not limited in size in 1965. All the basic concepts of hypertext were defined by the beginning of the 1970s. However, non-academic use of hypertext was not common until the 1990s, when the WWW appeared.
When computer scientist and inventor of the internet, John Berners Lee, spoke about making hypertext available on the World Wide Web through a web browser in 1990, he formulated three main criteria to support this process:
- a standardized address syntax for URIs (Uniform Resource Identifier), to uniquely identify individual resources on the internet
- a Hypertext Markup Language for the WWW (HTML)
- a Hypertext Transfer Protocol
The WWW is the most popular and widespread hypertext system today. Strictly speaking, it is a hypermedia system because it also allows the use and hyperlinking of video and audio content. Hypertexts on the WWW are written in what is called Hypertext Markup Language which is used to create HTML documents (websites).
In contrast to traditional text forms, hypertext is written in modules with no clearly defined reading order. Individual modules are integrated into the hypertext several times and linked to each other, which results in text structures that are easy to read despite their size and complexity. Note that this modularity means that each hypertext needs a certain degree of autonomy so that it can still be understood by its readers.
In principle, structured text and hypertext share some features, such as:
- clearly defined hierarchical structures (chapters and subchapters)
- linking elements (cross-references and references)
- different ways of accessing information (table of contents and index)
Books are usually read page by page, even if they have properties similar to those of a hypertext. The World Wide Web and its hypertext break this linearity because you do not have to read a hypertext entirely to get the desired information.
Evolution to Hypermedia
Hypermedia is an advancement of hypertext, which is driven in particular by the ever-increasing possibilities of the internet. It builds on the concept of hypertext and expands it by including audiovisual media like pictures, videos, or audio files. Hypermedia might sound similar to multimedia, but it is not the same. Multimedia-based presentation confronts users with content using several types of media at the same time. Hypermedia systems present information in different multimedia formats, which are structured in the same way as hypertext. The largest hypermedia system today is the World Wide Web.
Advantages and disadvantages
At present, hypertext is the most popular type of text on the World Wide Web. While it does have a lot of advantages, there are also disadvantages to it, as shown below.
Advantages of hypertext
- links in the text allow users to find additional information they have not explicitly searched for and would have missed otherwise
- clearly structured content and orientation possibilities
- uniform and cross-system user interface
Disadvantages of hypertext
- users can lose orientation due to too many links
- risk of information overload because of the high information density