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Hypermedia – An Introduction
What is Hypertext/Hypermedia
History of Hypertext/Hypermedia
Hypermedia Systems
Emerging Standards and Platforms
Applications
What is Hypertext/Hypermedia?
Regular Text vs. Hypertext– Sequential vs. nonsequential– Interface: a book vs. a computer system environment– Traditional author vs. “reader can be author”
Hypertext DefinitionHypermedia vs. MultimediaEssential Concepts of Hypertext/Hypermedia)– Nodes – Units of Information– Links – Labels connecting nodes– Navigation – Process of moving through the hypertext database
Hypertext/Hypermedia Terms
Hypertext Definition
Few Definitions: – A style of building systems for information representation and
management around a network of multimedia nodes connected together by typed links [Halasz, F.,1988]
– A database that has active cross-references and allows the reader to “jump” to other parts of the database as desired.
Nonsequential accessDocuments are shared across multiple locations/machines and allow collaboration
NODES: Units of Information
A node usually represents a single concept or idea.
Nodes are called frames (KMS), statements (Augment), articles (Hyperties), cards (HyperCard), and pages (WWW) in different systems.
Nodes can contain text, graphics, animation, audio, video, images, or programs.
Examples: management reports, statements of account, email, invoices, orders, design drawings, photos, video explanation of how-to-do, product catalogs, worksheets, sources codes, and others.
Links: Holding hypertext together
Links are the labels that connect one node with another.Links can be bi-directional (forward and backward), typed, referential or hierarchical. Links can– Transfer to a new topic– Show a reference– Provide ancillary information– Display an illustration, photograph, or video sequence– Display an index– Run another program
Navigation
The process of moving from one node to another through the hypertext webBROWSING: Making direct manipulation to explore a hypertext system
INDEXING: Making order of the chaos; an example
SEARCHING: Finding something– Keyword or text string search
FILTERS: Narrowing the search
TOURS– Follows a predefined path
BOOKMARKSPATH: Keeping track and going back
Hypermedia vs. Multimedia
Hypertext is text with pointers to other text.
Hypermedia is a superset of hypertext. Hypermedia documents contain not only text but also other digital formats - images, animation, video, and audio.
Multimedia systems make use of various data formats, but need not use the interactive techniques. Role of the user is more passive.
History of Hypertext/Hypermedia
1945 – Memex by Vannevar Bush
1962 – Augment by Douglas Englebart
1965 – Xanadu by Ted Nelson
1986 – Guide by Peter Brown
1987 – Hypercard by Bill Atkinson
1992 – Tim Berners-Lee unleashed the WWW
1993 – Mosaic
1994 – Netscape Navigator
1996 – Internet Explorer
Hypertext/Hypermedia Systems
A hypermedia system is a collection of tools that include hypermedia functionality. A tool is any program that helps users perform a specific task.
Components of a Hypermedia System
Closed Proprietary Hypermedia Systems vs. Open Internet Based Systems (i.e., WWW)
Components of a Hypermedia System
A graphical user interface helps the user to navigate through databases.An authoring system to create and manage nodes and linksInformation retrieval mechanisms to facilitate keyword searches, content queries.A hypermedia engine to manage information about nodes and links.A storage system which can be a proprietary file system or a knowledge base or a relational dbms or an object-oriented dbms.
Proprietary Hypermedia Systems
From mainframe-based, multiuser, text-only (Augment, Xanadu, FRESS) to workstation- and PC- based multimedia (Netpune, KMS, Guide, Hypercard), and to today’s client-server architecture (Dexter, Trellis, ToolBook, Microscom)
Closed Systems: documents created in one system cannot be easily integrated with documents created in another system
Multimedia
Graphical user interfaces
CD-ROM and WWW distributing media
Emerging Standards and Platforms
HTML
Images - GIF, JPEG, PNG
Audio - MP3, AU, MPEG, RA
Video - MPEG, QuickTime
Adobe’s PDF
TCP/IP
CD-ROM, DVD– distributing hypermedia
Desktop
Hypertext/Hypermedia Terms
Node: A unit of information. Also known as a frame, card, document
Link: A relationship between two anchors
Anchor: An area within the content of a node which is the source or destination of a link
Browser: A program which allows a person to read hypertext
Navigation: The process of moving from one node to another through the hypertext web
More . . .Source: http://www.w3.org/Terms.html
