Introduction to HCI
CS4HC3 / SE4HC3/ SE6DO3Fall 2011
Instructor: Kevin [email protected]
Slide content is based heavily on Chapter 1 of the textbook: Designing the User Interface: Strategies for Effective Human-Computer
Interaction / 5th edition, by Ben Schneiderman & Catherine Plaisant
Introduction to HCI
● What is HCI?● Measuring HCIs● Motivations● Universal usability● Goals of HCI profession
What is HCI?
● Human Computer Interface (or Interaction)● Design, implementation, evaluation and study of
human-computer interaction● User interface: where the interaction occurs
● Interdisciplinary design science ● Computer science, psychology (especially
experimental psychology...), hardware, software engineering, graphic design, ergonomics, sociology, economics, business...
Exciting time for HCI field!
● Transition away from desktop software● Mobile computing
– Smartphones– Tablets
● Cloud computing
● Transition away from keyboard and mouse● Accelerometer● Touch screen● Motion sensing (e.g. Kinect)
Measuring HCIs
● ISO 9241 standard Ergonomics of Human-System Interaction (ISO, 2008) ● Goals:
– Effectiveness– Efficiency– Satisfaction
● Contains guidance, principles, framework, design criteria, test methods, etc.
Measuring HCIs
● Measurements for practical evaluation of HCIs:● Time to learn● Performance (e.g. speed, error rate)● Retention● Subjective satisfaction● Subjective trustability
● Relative importance of desirable qualities varies depending on requirements, target users, etc.
Measuring HCIs● Measurements can be different across different
applications ● E.g. “performance” may be speed, total work
accomplished within a set time, etc.
● Often times unavoidable trade-offs between these desirable HCI qualities exist
● Often improving one desirable HCI quality improves others, e.g. improved learnability may increase subjective satisfaction
Motivations
● What software domains are motivating HCI research and what are the typical design trade-offs in the domains?
● Life-critical systems● Air traffic, police/fire, military, power plants, etc.● Design trade-off considerations:
– Time to learn can be high, training expected– Performance regarding speed, error rate, should be high– Subjective satisfaction less important
Motivations
● Industrial and commercial uses● Banking, inventory, airline/hotel reservations, order
entry, point-of-sale terminals, ATMs, etc.● Design trade-off considerations:
– Speed of performance typically of high importance– Error rate importance typically depends on cost trade-off
with speed– Subjective satisfaction only of modest importance
Motivations
● Home and entertainment applications● Smartphones, mp3 players, tablet computers, video
game consoles, digital cameras, etc.● Design trade-off considerations:
– Low time to learn, error rates desired – High subjective satisfaction desired
● Layered design from novice to expert usage● e.g. Basic search engine to advanced search features
● Feature-bloat can be an issue, simplicity often achieved by reducing or trimming features
Motivations
● Exploratory, creative, collaborative software● Search engines, scientific or business collaboration
supporting applications, music-composition or video editing software, etc.
● Design trade-off considerations:– How to even objectively measure “performance” for these
kinds of applications?– Time to learn often important– Often, best scenario is to have the interface “vanish”
through a direct manipulation interface...
Motivations
● Sociotechnical systems● Complex long-term systems involving many people● Electronic voting, health care, crime reporting, etc.● Often created by governments● Design trade-off considerations:
– Trust of users is paramount– Time to learn important
Motivations
● New hardware changes are motivating HCI...● Smartphones, tablets● Natural user interfaces: touch screen,
accelerometer, motion sensing, voice recognition, etc.
● New software challenges are motivating HCI...● How do we provide a UI for a website across many
different desktop, smartphone and tablet platforms?
Universal usability
● UI challenge: diversity of user backgrounds, abilities, cultures, personalities
● Meeting challenge critical to:● Enabling full participation for everyone● Expanding market share
● Accommodation for a specific group doesn't mean “dumbing down” a UI
Universal usability
● Accommodation often pays off for other groups● Curb cuts in sidewalks for wheelchair users benefit
parents with strollers, people with luggage, etc.● Text-to-speech conversion can help sighted users
– e.g. UI reading off text messages while driving a car● Helping seniors access e-mail, text messaging,
social networking also helps them keep in touch with their family and continue to contribute to society
Universal usability
● Things to accommodate:● Variations in physical abilities and physical
workspaces● Diverse cognitive and perceptual abilities● Personality differences● Cultural and international diversity● Users with disabilities● Older adult users● Children● Hardware and software diversity
Universal usability
● Variations in physical abilities and physical workspaces● Anthropometry: scientific study of measurements
and proportions of the human body– Data from anthropometry key to design, e.g. Touchscreen
keypad key distance based on finger size ranges● Perception ability differences
– Motion sensitivity, screen brightness, corrected vision ● Workspace differences
– Noisy environment? Poor lighting? Temperature?
Universal usability
● Diverse cognitive and perceptual abilities● Short-term, long-term memory● Problem solving and decision making ● Language communication and comprehension● Learning, skill development, knowledge aquisition● Fatigue and sleep deprivation● Monotony and boredom● Mood, emotion● Inebriation
Universal usability
● Personality differences● Male, female differences?
– Conjectures, but no clear pattern of differences● Myers-Briggs
– Extroversion versus introversion– Sensing versus intuition– Perceptive versus judging– Feeling versus thinking
● Organized vs unorganized approach to files, e-mails, data?
Universal usability
● Cultural and international diversity issues...● Character sets● Left-to-right vs. Right-to-left reading● Date and time formats● Weights and measurements● Names and titles● Etiquette, policies, tone, formality and metaphors
Universal usability
● Users with disabilities● Recent legislation increases demand, importance...
– United States: Amendment to Section 508 of the Rehabilitation Act requires access to IT by employees and the public
● Accommodation:– Screen magnification– Text-to-speech conversion– Visual indications of auditory alarms\sginals– Closed captioning
Universal usability
● Older adult users● Important concern due to aging population● Problems
– Visual\auditory acuity, strength, and response speed decline
– Memory function loss– Increased difficulty in acquiring new and complex mental
skills● Continued endeavours of experienced adults can
greatly benefit society
Universal usability
● Children● Different financial resources and learning
environments– Some may be frustrated by technology
● Limited abilities– Critical thinking– Dexterity
● Dangers– Exposure to inappropriate material
Universal usability
● Accommodating hardware and software diversity● High-speed vs low-speed internet ● Enabling web access across all devices
– Small mobile device screens to desktop screens● Supporting translation \ conversion of UI to multiple
languages, cultures● Different inputs: touchscreen, keyboard & mouse
Goals for HCI Profession
● Goals for HCI profession:● Influencing academic and industrial researchers● Providing tools, techniques and knowledge for
commercial designers● Raising the computer consciousness of the general
public
Influencing academic and industrial researchers
● Introspection, intuition for HCI design insufficient
● Rigour needed: Scientific method, experiments– Understand problem, related theories– Testable hypothesis– Select subjects – Manipulation of independent variables– Measurement of dependent variables – Apply statistical tests to acquired data – Interpret results, refine theories– Validate results through replication
Influencing academic industrial researchers
● Controlled experiments typically short-term, but what about long-term HCI observations?● Automated logging of user behaviour● Surveys● Focus groups● Interviews● Online feedback: forums, wikis, social networks
Influencing academic and industrial researchers
● Need for more HCI research exists...● Reduced anxiety and fear of computer usage● Graceful evolution● Social media participation● Input devices (relative merits)● Online help● Information exploration● And many more areas...
Providing tools, techniques, and knowledge for commercial designers● Usability increasingly no longer seen as a
secondary topic: more UI designers, testers● Competitive advantage recognized
● Require user interface building tools● Different tools for different problems...
● Desire techniques, guidelines ● UI guidelines exist for major platforms
– iOS, Android, WP7
● Desire UI feedback during, after development● Surveys, interviews, empirical tests, etc.