Introduction to HCI

CS4HC3 / SE4HC3/ SE6DO3Fall 2011

Instructor: Kevin Brownebrownek@mcmaster.ca

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.

References

Designing the User Interface: Strategies for Effective Human-Computer Interaction / 5th edition, by Ben Schneiderman & Catherine Plaisant (2010)