Introduction to HCI - Department of Computer and Information

CEN 4721C / CAP 5100
Andrea Kleinsmith, Ph.D.
What are your goals for the class?
• What is Human-Computer Interaction?
• Man-Machine Interaction
• Computer-Human Interaction
• What are your learning objectives?
• How much effort do you want to expend for
learning those objectives?
What the class will look like
 Lectures (participation grade)
 Readings + Quizzes
 Projects
 Initial user study – individuals
 Final project – teams
Identify a client
Create a new interface
Evaluate the interface
 Midterm paper
 Differences between undergrad/grad
 Project requirements
Why take this course?
• Build your portfolio
• Work on a project you have always wanted credit to
work on
• Study a unique topic
• A computer science course focused on users
• Skill building
• Important in most research
• Burgeoning job field
Common Questions
 Q: What programming language will we use?
 A: Anything you want, but we will provide sample code
in Java.
 Q: Do I need to know how to program?
 A: You should be proficient in Java at a Data Structures
 Q: Do I need to know computer graphics?
 A: No.
 Q: How many A’s do you give out?
 A: As many as who earn it. Typically, if you ask this
question, you are in the wrong class.
• What is a user interface?
• Why do we care about
• We see this all the time
• What’s good about the design
of this error box?
• The user knows there is an error
• What’s poor about the design of this error box?
• Discouraging (who gets the blame?)
• Not enough information
• No way to resolve the problem (instructions or contact info)
• Whose fault is this?
Definition of HCI
• “Human-computer interaction is a discipline
concerned with the design, evaluation and
implementation of interactive computing
systems for human use and with the study of
major phenomena surrounding them.”
• ACM SIGCHI Curricula for HCI (Hewett et al. 1992)
Why HCI is Important
• It can affect
• Activity: Consider a program, device, or product’s
How would you describe the interface?
How would you describe the product to your friend?
Would you buy the product again?
Would you buy a product from the same company
What words would you use?
How can companies design positively?
What makes or breaks a product?
What fields does HCI cover?
• Computer Science
• Psychology
• Affective Computing
• Communication
• Education
• Anthropology
• Design (e.g. graphic and industrial)
What will I learn in this class?
• How to design interfaces
• Example: Amazon One-Click
• How to evaluate interfaces
• Example: UF ISIS
• Not how to program interfaces
• Example: Design a better calculator
Norman Doors
Bad Interfaces
• Encumbering
• Confusing
• Slow
• Trust (ex. windows
• What makes it hard?
• Varies by culture
• Multiple platforms
• Variety of users
Good or bad design?
Good or bad design?
• What’s wrong with each?
• Who is affected
• Impact
• What’s a redesign solution?
Importance of Design
So how do you avoid bad design?
• Activity
• Design the ultimate fast food drive thru
Did your design support?
• A customer who can’t read English?
• A customer who is hearing impaired?
• A customer who has never eaten a hamburger before?
• A customer who is health conscious?
• A customer who has an IQ of less than 80?
• A customer who is over 7’ tall
• Did you design an interface for you?
• Is not that what someone already did?
Good Design
• You can’t create one just by sitting around and
dreaming one up
• Rely on
• Known design solutions
• User evaluations
• Must provide
• Usability
• Universality
• Usefulness
Requirements analysis
• In designing a building I want inhabitants to move
between floors
Ascertain users’ needs
Ensure proper reliability
Promote appropriate standardization, integration,
consistency, and portability
Complete projects on schedule and within budget
Ascertain user’s needs
• Define tasks
• Tasks
• Subtasks
• Frequency
• Frequent
• Occasional
• Exceptional
• Repair
• Ex: Difference between a
bike, a car and an airplane
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Ensure reliability
 Actions function as specified
 Data displayed must be correct
 Updates done correctly
 Leads to trust! (software,
hardware, information) – case:
1994 Pentium FDIV bug
 Cost to Intel: $475 million
 Privacy, security, access, data
destruction, tampering
Standardization, Integration,
Consistency, Portability
 Standardization – common user-interface features
across multiple applications
 Apple
 Web
 Windows
 Smart phones
 Integration – product should run across application
 file formats
 Consistency – common action sequences, terms, units,
layouts, color, typography within an application
 Portability – allow user to convert data and interfaces
across multiple hardware and software environments
Usability measures
• How can we measure the
‘goodness’ of an interface?
• What are good metrics?
• ISO 9241
• Effectiveness
• Efficiency
• Satisfaction
• Shneiderman
• Time to learn
• Speed of performance
• Rate of errors
• Retention over time
• Subjective satisfaction
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Usability Motivations
• Life-Critical systems
•Time to learn
•Speed of performance
•Rate of errors
•Retention over time
•Subjective satisfaction
• Applications: air traffic, nuclear reactors, military, emergency
• Requirements: reliability and effectiveness (even under stress)
• Not as important: cost, long training, satisfaction, retention
• Industrial and Commercial Use
• Applications: banking, insurance, inventory, reservations
• Requirements: ease of use/learning to reduce training costs,
multiple languages, multiplatform, speed of performance
• Office, Home, and Entertainment
• Applications: email, games, search engines, cell phones
• Requirements: Ease of learning/use/retention, error rates,
satisfaction (competition is fierce)
Usability Motivations
•Time to learn
•Speed of performance
•Rate of errors
•Retention over time
•Subjective satisfaction
• Exploratory, Creative, Collaborative
• Applications: search engines, simulations, scientific
visualization, CAD, computer graphics, music
composition/artist, photo arranger (email photos)
• Requirements: the ‘computer’ should be transparent so
that the user can be absorbed in their task domain
• Difficulties: user tech savvy-ness
• Socio-technical systems
• Applications: health care, voting, police
• Requirements: Trust, security, accuracy, error handling,
user tech-savvy-ness (need tools to detect unusual
patterns of usage)
Universal Usability
• Interface should handle diversity
of users
Technical capacity
• Question, how would you design an
interface to a database differently for:
A. right-handed female, Indian, software
engineer, technology savvy
B. left-handed male, French, artist
Universal Usability
• Does not mean ‘dumbing
• Ex. Crosswalks (parents w/
strollers, elderly, diff cultures)
• Goal: Address the needs of
more users - unlike yourself!
• Everyone is often not at full
faculties at all times
Physical Variation
• Field of anthropometry
• Basic data about human
• Is no ‘average’ user
• Measures of what is 5-95% for
weight, height, gender, culture,
• Large variance reminds us
there is great ‘variety’
• Name some devices that this
would affect…
Physical Variation
• Work-surface and display-support
• Clearance under work surface for
• Work-surface width and depth
• Adjustability of heights and angles
for chairs and work surfaces
• Posture - seating depth and angle;
back-rest height and lumbar
• Availability of armrests, footrests,
and palmrests
Cognitive and perceptual abilities
• The journal Ergonomics Abstracts offers this
classification of human cognitive processes:
• Long-term and semantic memory
• Short-term and working memory
• Problem solving and reasoning
• Decision making and risk assessment
• Language communication and comprehension
• Search, imagery, and sensory memory
• Learning, skill development, knowledge acquisition, and
concept attainment
Cognitive and perceptual abilities
• However, perceptual and motor performance can
be affected by these factors:
• Fatigue and sleep deprivation
• Cognitive load
• Monotony and boredom
• Nutrition and diet
• Fear, anxiety, mood, and emotion
• Drugs and alcohol
• No set taxonomy for identifying personality types
• Myers-Briggs Type Indicator
• extroversion vs introversion
• sensing vs intuition
• perceptive vs judging
• feeling vs thinking
• Big Five Test
• Openness to experience (open/closed)
• Conscientiousness (disorganized/organized)
• Extraversion (extraverted/introverted)
• Agreeableness (disagreeable/agreeable)
• Neuroticism (calm/nervous)
Cultural and International Diversity
• Language
• Date / Time conventions
• Weights and Measures
• Reading: left-to-right, up-and-down
• Telephone #s and addresses
• Names, titles, salutations
• SSN, ID, passport
• Icons, buttons, colors
• Etiquette, tone, formality
Users with Disabilities
• 1998 Amendment to Rehabilitation Act
• Federal law to ensure access to IT, including computers
and web sites
• Vision (text-to-speech)
• Blind (bill-reader)
• Low-vision
• Color-blind
• Hearing (conversion of tones to visual signals)
• Deaf
• Limited hearing
• Mobility (eye-gaze control, head-mounted optical mice)
• Learning
• Dyslexia
• Attention deficient, hemisphere specific, etc.
• Keyboard, mouse, color alternatives
• Reduced
Motor skills
Vision, hearing, touch, mobility
• Other needs
• Technology experience is varied (How
many grandmothers use email?
• Uninformed on how technology could
• Practice skills (hand-eye, problem
• Touch screens, larger fonts, louder
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• Technology familiarity
• Age changes:
• Physical dexterity
• (double-clicking, click and drag, and small
• Attention span
• Varied backgrounds (socio-
• Goals
• Educational acceleration
• Socialization with peers
• Psychological – improve self-image,
• Creativity – art, music, etc. exploration
• Teenagers are a special group
• Next generation
• Beta test new interfaces, trends
• Cell phones, text messages, simulations, fantasy games,
virtual worlds
• Requires Safety
• They
• Like exploring (easy to reset state)
• Don’t mind making mistakes
• Like familiar characters and repetition
• Don’t like patronizing comments, inappropriate humor
• Design: Focus groups
Goals for Academic HCI
• Provide tools, techniques and knowledge for
commercial developers
• Competitive advantage (think iPad)
• Raising the computer consciousness of the general
• Reduce computer anxiety (error messages)
• Common fears:
• I’ll break it
• I’ll make a mistake
• The computer is smarter than me
• HCI contributes to this!