Introduction to HCI. CS4HC3 / SE4HC3/ SE6DO3 Fall Instructor: Kevin Browne

Transcription

1 Introduction to HCI CS4HC3 / SE4HC3/ SE6DO3 Fall 2011 Instructor: Kevin Browne brownek@mcmaster.ca Slide content is based heavily on Chapter 1 of the textbook: Designing the User Interface: Strategies for Effective Human-Computer Interaction / 5 th edition, by Ben Schneiderman & Catherine Plaisant

2 Introduction to HCI What is HCI? Measuring HCIs Motivations Universal usability Goals of HCI profession

3 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...

4 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)

5 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.

6 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.

7 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

8 Motivations What software domains are motivating HCI research and what are the typical design tradeoffs 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

9 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

10 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

11 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...

12 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

13 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?

14 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

15 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 , text messaging, social networking also helps them keep in touch with their family and continue to contribute to society

16 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

17 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?

18 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

19 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?

20 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

21 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

22 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

23 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

24 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

25 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

26 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

27 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

28 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...

29 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.

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