2. Outline
Course Info & Syllabus
Course Overview
Introductions
HCI Overview
A brief history
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3. Course Aims
Consciousness raising
– Make you aware of HCI issues
Design critic
– Question bad HCI design - of existing or proposed
Learn Design Process
– Software interfaces and beyond
Improve your HCI design & evaluation skills
– Go forth and do good work!
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4. Course Overview
Requirements Gathering
– How do you know what to build?
– Human abilities
Design
– How do you build the best UI you can?
Evaluation
– How do you make sure people can use it?
Also cognitive and contextual models, interface
paradigms, design guidelines, web and
visual design, and advanced topics4
5. HCI
The interaction and interface between a
human and a computer performing a task
– Tasks might be work, play, learning,
communicating, etc. etc.
– Write a document, calculate monthly budget,
learn about places to live in Charlotte, drive
home…
…not just desktop computers!
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6. Why do we care?
Computers (in one way or another) now affect every
person in our society
Tonight - count how many in your home/apt/room
We are surrounded by unusable and ineffective
systems!
Its not the user’s fault!!
Product success may depend on ease of use, not
necessarily power
You will likely create an interface for someone at some
point
– Even if its just your personal web page
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7. Goals of HCI
Allow users to carry out tasks
– Safely
– Effectively
– Efficiently
– Enjoyably
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8. Usability
Combination of
– Ease of learning
– High speed of user task performance
– Low user error rate
– Subjective user satisfaction
– User retention over time
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9. Design Evaluation
Both subjective and objective metrics
Some things we can measure
– Time to perform a task
– Improvement of performance over time
– Rate of errors by user
– Retention over time
– Subjective satisfaction
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11. Know Thy Users!
Physical & cognitive abilities (& special needs)
Personality & culture
Knowledge & skills
Motivation
Two Fatal Mistakes:
– Assume all users are alike
– Assume all users are like the designer
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12. Design is HARD!
“It is easy to make things hard. It is hard to
make things easy.” – Al Chapanis, 1982
Its more difficult than you think
Real world constraints make this even harder
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14. Batch processing
Computer had one task,
performed sequentially
No “interaction” between
operator and computer after
starting the run
Punch cards, tapes for input
Serial operations
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15. Paradigm: Networks & time-sharing
(1960’s)
Command line teletype
– increased accessibility
– interactive systems, not jobs
– text processing, editing
– email, shared file system
Need for HCI in the design of programming
languages
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16. The Ubiquitous Glass Teletype
Source: http://www.columbia.edu/acis/history/vt100.html
24 x 80 characters
Up to 19,200 bps
(Wow - was big
stuff!)
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17. Paradigm: Personal Computer
Small, powerful machine dedicated
to an individual
Importance of networks and time-
sharing
Also:
– Laser printer (1971, Gary
Starkweather)
– Ethernet (1973, Bob Metcalfe)
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18. Paradigm: WIMP / GUI
Windows, Icons, Menus, Pointers
Graphical User Interface
Multitasking – can do several things simultaneously
Has become the familiar GUI interface
Computer as a “dialogue partner”
Xerox Alto, Star; early Apples
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19. Xerox Star - 1981
First commercial PC designed
for “business professionals”
– desktop metaphor, pointing,
WYSIWYG, high degree of
consistency and simplicity
First system based on usability
engineering
– Paper prototyping and analysis
– Usability testing and iterative
refinement
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20. Apple Macintosh - 1984
Aggressive pricing - $2500
Not trailblazer
Good interface guidelines
3rd
party applications
High quality graphics and
laser printer
“The computer for the rest of
us”
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21. Paradigm: WWW
Hypertext around since the 1960’s…
Two new components
– URL
– Browser
Tim Brenners-Lee did both
– 1991 first text-based browser
Marc Andreesen created Mosaic (first
graphic browser, 1993)
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24. Course ReCap
To make you notice interfaces, good and
bad
– You’ll never look at doors the same way again
To help you realize no one gets an
interface right on the first try
– Yes, even the experts
– Design is HARD
To teach you tools and techniques to help
you iteratively improve your designs
– Because you can eventually get it right
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Editor's Notes
Construction: Monitor + detachable keyboard
Display: 24x80 or 14x132 character cells, optional 24x132
Character matrix: 7x9 with descenders
Screen size: 12" diagonal (8" x 4.5" active display)
Character set: Complete US ASCII (128 codes)
Keys: 65 keys in ANSI X4.14-1971 typewriter layout
http://www.columbia.edu/acis/history/vt100.html
Auxiliary keypad: 18 keys (digits, arrows, function keys)
Visual indicators: 7 LEDs
Interface: RS-232/V.24, optional 20mA Current Loop
Flow control: Xon/Xoff
Communication Speeds: 75,110,150,300,600,1200,2400,4800,9600,19200 bps
Dimensions: 14.5"x18"14.25" (monitor), 3.5"x18"x8" (keyboard)
Minimum table depth: 20.25"
Weight: 41 pounds
But it was a flop – too expensive, closed architecture, no spreadsheet