HYPERMEDIA Chang-Yang Lin Eastern Kentucky University

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 Definition Hypermedia vs. Multimedia Essential Concepts of Hypertext/Hypermedia) –Nodes – Units of InformationNodes –Links – Labels connecting nodesLinks –Navigation – Process of moving through the hypertext databaseNavigation 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 access Documents 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, , 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 web BROWSING: Making direct manipulation to explore a hypertext system INDEXING: Making order of the chaos; an examplean example SEARCHING: Finding something –Keyword or text string search FILTERS: Narrowing the search TOURS –Follows a predefined path BOOKMARKS PATH: 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 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 links Information 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 NodeNode: A unit of information. Also known as a frame, card, document LinkLink: 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 NavigationNavigation: The process of moving from one node to another through the hypertext web More... Source: