1.2.1. Hypertext

1945: Vannevar Bush and the MEMEX machine

Generally, the concept of multimedia is based on the concept of hypertext which was invented in the early 1940ies.

In 1945 Vannevar Bush wrote an article about a virtual machine (Memex: Memory Extender) which was able to browse and annotate large collections of documents including a mechanism to create links between various documents. (BUSH 1945)

From Bush's concept evolved the concept of hypertext systems. Hypertext is text which is extended by links. These links act as pointers to other pieces of text that are located elsewhere, either in the same document or in another document or both. Using these links enables users to "browse around" in one or more documents.

Vannevar Bush (Wikipedia)

Concept of Hypertext

From Bush's concept evolved the concept of hypertext systems. Hypertext is text which is extended by links. These links act as pointers to other pieces of text that are located elsewhere, either in the same document or in another document or both. Using these links enables users to "browse around" in one or more documents as you can experience in the following example.

Concept of Hypermedia

Hypertext can be extended to Hypermedia that supports the linking of graphic, sound and video elements in addition to simple text elements. A hypermedia-application is basically based upon two different concepts:

• page-based
  Text and images are arranged in a two-dimensional system that is similar to the way text and images are arranged in textbooks and journals. Time-dependent elements (e.g., video and sound) are embedded within the page as if they were images.

  
  
  Example of a page-based application
  

• synchronization-based
  Time is the central organizing principle. Elements are arranged in time and often a timeline is used so that they are presented as a sequence.

  
  
  Example of a synchronization-based application (National Statistics UK)
  

As it has been discussed, both the page-based and the synchronization-based concept have arisen in the 1940ies. Yet only after several years of development could these concepts be converted into running applications as it is shown in the above examples.