CS 407 Human Computer Interface

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CS 407 Human Computer Interface

• Class 15
• Wednesday, September 29, 1999

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Thought for the Day

• The only thing necessary
• for the triumph of evil
• is for good men to do nothing.
• -Edmund Burke
• (1729-1797)

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Todays Topics

• Chapter 4.2-4.4 today.
• Any questions on Project?
• Project Due date 10/11!
• (Changed by popular demand!)
• Start Chapter 5 Friday

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HCI Websites (1)

• ACM SIGCHI HCI-Sites (Lots of good links!)
• Web Design and Usability Hotlist (Good links!)
• Jakob Nielsen's Column on Web Usability
• Web Review - Usability Links (Jakobson, etc.)
• http//www.iarchitect.com/index.htm
• WebHCI

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HCI Websites (2)

• User Interface Engineering
• www.webpagesthatsuck.com
• http//www.asktog.com/
• Microsofts User Experience UI Resources
• Please let me know of other good sites!

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Chapter 4 Usability Paradigms and Principles

• Paradigms for usability.
• Examples of successful interactive techniques.
• Principles for usability.
• Theoretically driven.
• Based on psychological, computational and
  sociological knowledge.

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Paradigms for usability

• Historical Perspective
• Batch processing
• Time-Sharing
• Video Display Units (VDU)

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Programming Toolkits

• Douglas Engelbart at Stanford Research Institute
  in 1963 thought of using computers to augment
  man's intellect.
• If your only tool is a hammer, every problem
  looks like a nail. ? Better Tools!
• 1968 NLS/Augment system demonstration.
• The right programming toolkit provides building
  blocks to producing complex interactive systems.

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Personal Computing

• Seymour Papert LOGO language for simple graphics
  programming by children.
• A system is more powerful when it is easier to
  use.
• Future of computing was in small, powerful
  machines dedicated to the individual.
• Alan Kay (Xerox, Apple) envisioned the Dynabook
  in the 70s!

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Windows systems and WIMP

• Humans often pursue more than one task at a time.
• Windows used for dialogue partitioning, to
  "change the topic.
• 1981 Xerox Star first commercial windowing
  system.
• Windows, Icons, Menus and Pointers now familiar
  interaction mechanisms.

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The Metaphor

• Relating computing to other real-world activity
  is effective teaching technique.
• LOGO Turtle drags its tail to draw.
• File management on an office desktop.
• Word processing as typing.
• Financial analysis on spreadsheets.
• Virtual reality user is inside the metaphor.

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Metaphor Problems

• Some tasks do not fit the metaphor.
• Typing ? Word processing.
• Space and return are very different!
• Desktop metaphor
• How do you eject a disk from a desktop?
• How do you print on a desktop?
• Cultural bias.
• What if users have never seen a desktop?

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Direct Manipulation

• Shneiderman (1982) describes the appeal of a
  graphically based interaction.
• Visibility of objects.
• Incremental action rapid feedback.
• Reversibility encourages exploration.
• Syntactic correctness of all actions.
• Replace command language with action.

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Direct Manipulation (2)

• Apple Macintosh (1984) was the first widely used
  system to use direct manipulation.
• The Model-World metaphor.
• Make changes in the model, and the world is also
  changed.
• What You See Is What You Get WYSIWYG
• But! WYSIAYG ? ALL you get!

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Language vs. Action

• Actions do not always speak louder than words.
• DM interface replaces underlying system.
• Language paradigm.
• Interface as mediator .
• Interface acts as intelligent agent.
• Programming by example is both action and
  language.