21 Hypertext, Multi-media and the WWW

Text is linear
Hypertext: non-linear linkage
	Multi-media (sounds, images, video, animation)

WWW (subset of internet)
	Global hypermedia system with multi-media embedding possible
	If a picture is worth 1000 words,
		What is the value of:
		Animation
		Video
		Interactive simulation
		Virtual reality
	Online help, education, ecommerce
	Hypermedia has its own issues
	Bookmarks, back buttons, search, help
	Static, and dynamic

20.1 power of computing has made much possible
	Gamers are on the frontier of developing CIS
	(On-line porn is also a commercial motivator)
20.2 understanding hypertext
	Text has been linear
	Online help needs to be non-linear
	Exploratory learning needs to be non-linear
	Even print encyclopedias saw the need for non-linear
	Index, articles, see also concordance, search 
	[choose your own story]
	To emphasize media, call it multi-media
	To emphasize both, call it hypermedia
	Pages, and links, multiple links possible per page
	[drawing a diagram can be difficult]
Rich content
	Animation
		Clock
		Even a cursor can be animated
		Hourglass, watch, spinning dial, weightlifting stick figure
		Sliders, bars that fill
		Minimize to avoid distraction
		Clippy and the dog (Word)
		Talking heads
			Emotional connection
		Video and audio
		Can be expensive and time consuming
		Home systems can now do animation
		Memory requirements
		Gaming systems
		Compression (sound harder than video)
		MP3, MIDI
		Let user turn off sound!
		Study of how TV and movies work may benefit animation in the future
	Computation, intelligence, interaction
		Can show and do
		Search
		Embedded games and applications
		Can shape the experience based on a model of the user
				Or experience of the user
		Suggested products

	Delivery technology
		Permanent installation
		CD-ROM
		Download as needed
		Special player
		Web page not automatically better than a book
			Need good design
			Usability beat technology
		Mobile phones, PDA, notebook computers, tablets
			Increased demand for mobile bandwidth (wi-fi, cell)
	Application areas
		Rapid prototyping
			Hypercard, notcard metaphor
			Macromedia, director
		Help and documentation
		Education and e-learning
			CAL computer assisted learning
			CAI computer assisted instruction
			CUE computer uses in education
			PLATO (U of IL) 
		Collaboration and community
			Loyalty is a business value
		E-commerce
			Trust is an issue
			(reliability, returnability, quality)
21.3 finding things
	Don’t get lost in hyperspace
	Writer of a page does not know what reader has seen
	(integration and redundancy issues)
	Hard to track as you move
	(record where you have been in a way you can access)

	Designing structure
	(see chapter 15; pre-existing structures)
	By purpose, by location, by color, by price,….
	Can have multiple structures that have common material
	Description may be different depending on perspective coming from
		(mechanic, driver, passenger….)

	Coming from
		Make navigation easier
		Map
		Sidebar
		Breadcrumbs
		Recommended routes
		Levels of access
			Overview at high level for orientation
			Details at lowest level
		Can be hard to print things
			Printer friendly pages
			Screen shot
			Printed therefore no longer hypertext
			(At least print URL, copyright notice)
	History bookmarks external links
		History and back button (30% of usage on a web page)
		Hub and spoke
		Bookmarking
		Deep linking
			Cannot back up
			Bypass entryway
		Framed web sites
			Makes linking harder
		Indices, directories, search
			Index can be big
			Directory can help organization
			Keyword search
				Stored in advance or re-compute?
				Search pages, search database?
				Web content keeps changing
				Meta words, title
					(don’t use distractors)
				Number of times words are used
				Phrases
				Popularity
				(profit)
				How many pages link to this page
				How many good pages this page links to

			Ratings
			Ask a librarian
				Peer review
				Publisher
				Purpose
				Perspective
21.4 web technology and issues
	Basics
		HTML/XML/PHP
		Browsers
		Plug ins
		Information overload
	Web servers and clients
		Web is distributed
	Network
		Bandwidth
		Latency (jitter)
		Lossy protocols
		Rapid feedback
			Client end
			PHP, Javascript, AJAX
21.5 static web content
	CONTENT
		Easy to publish nonsense, propaganda, incomplete, poorly written
		Poor design can make good material look bad
		Flashy design can make bad material look good
		Watch for confirmation bias
		Make sure content you look for is good
		Please make YOUR content both good and well presented
	Text
		Not all fonts are available on all pages
		Fixed point fonts may not display 
		Visually impaired dislike fixed sizes
		Color is often abused
		Links are colored
		Background is colored
		Text is colored
In the event we do not have time, notes from the rest of the chapter are included.
		INTERRUPTION
		Justify left right center; indentation; lists, tables, CSS
		Don’t forget people using cell phones
		Displaying equations is a problem

	Graphics
		Images slower to load than text
		Picture is 1000 words but 50 times longer to load
		Complex backgrounds add little
		Caching makes reuse of images easier
		Graphics can be assembled from cached pieces
		Image loading can be turned off
		Text based browsers
		Alt=
		GIF (lossless; animated)  and JPEG (lossy) 
can be progressively transmitted (start blurry)
		image maps: hard to tell what is active
	icons
		need thought to represent functionality
		rarely seen on their own (clash)
		check how used in other systems
	graphics and colors
		older machines have fewer colors
		limit to 216 colors when possible
		fewer bits means speedup
		screens usually 72 dpi; high res loses
	movies and sound
		downloading
		streaming media
			high compression; large buffers
		
	under construction
		
21.6 dynamic web content
	Active web
		No longer static repository
	What happens where (807 of 861)
		What (media, presentation, data)
		By whom (computer, author, end user, another user)
		How often (pace)
		Where (client, server, another machine, human system)
		Big effects feedback, feedthrough, data location, and security
	User view
	
Fixed content or dynamic pages
	If you re-load a page, does application start over?
Search
	Usually server based
Automatic generation
	Automatic generation of web html
Batch generation
Dynamic content
	updateable
	seat reservations
	authentication
21.7 summary