This document provides an overview of a Human Computer Interaction course. It discusses the course aims of raising consciousness about HCI issues, teaching the design process, and improving HCI skills. The course covers requirements gathering, design, evaluation, and models of cognition and context. It reviews the history of interaction paradigms from batch processing to command lines to graphical user interfaces. The goals of HCI are to allow users to complete tasks safely, effectively, efficiently and enjoyably. Design evaluation considers both subjective and objective metrics. The document emphasizes the importance of understanding users and iterative design.

1. Human Computer Interaction
Khalid Mahmood (MSCS)
k.mah.khan@live.com

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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10. UI Design / Develop Process
 User-Centered Design
– Analyze user’s goals & tasks
– Create design alternatives
– Evaluate options
– Implement prototype
– Test
– Refine
– IMPLEMENT
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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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13. The past…
Time
UserProductivity
Batch
Command
Line
WIMP
(Windows)
1940s – 1950s 1980s - Present1960s – 1970s
?
?
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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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22. New paradigms?
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23. And the future?
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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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