HCI - 2 - Usability & User Experience.pdf

Usability & User Experience

1. Usability &
User Experience
Human Computer Interaction

2. References
•Shneiderman, B., Chaterine Plaisant. DesigningThe
UserInterfaceFifthEdition(Chapter1 & 2). PearsonAddison Wesley
•Sharp, H., Rogers, Y., Preece, H., InteractionDesign
5th edition
•Others

3. Which one are you?

4. What’s the importance of good UI?
•Computer àSocial Computer
•Produce competition and sensation
•Change many people’s live

5. USABILITY

6. WhatIs
Usability?
•UserFriendly... easy to use; accessible; comprehensible; intelligible; idiot proof; available; and ready(synonymin Microsoft Word 2002)BUT.....•Afriendalsoseeks to help and be valuable. •A friend is not only understandable, butunderstands. •A friend is reliable and doesn’t hurt. •A friend is pleasant to be with.

7. Usability goals
•Effective to use
•Efficient to use
•Safe to use
•Have good utility
•Easy to learn
•Easy to remember how to use

8. Every designer would like to succeed in every
measure, but there are often forced tradeoffs
Usability
Measures
•Time to learn
•Speed of performance
•Rate of errors by users
•Retention over time
•Subjective satisfaction

9. Goals for Requirement Analysis
•Ascertain the user’s needs
•Ensure Reliability
•Promote standardization, integration, consistency, and portability
•Standardization
•Integration
•Consistency
•Portability
•Complete projects on time and within budget

10. Usability Motivation
Professional Environment: Life CriticalSystem
•Air traffic control, nuclear reactors, power utilities, police &
fire dispatch systems, medical equipment
•High costs, reliability and effectiveness are expected
•Length training periods are acceptable
•Subject satisfaction is less an issue due to well motivated
users
•Retention is obtained by frequent use of common functions
and practice sessions for emergency actions.

11. Usability Motivation (Cont)
Professional Environment: Industrial andCommercialUse
•Banking, insurance, order entry, inventory management,
reservation, billing, and point-of-sales systems
•Ease of learning is important to reduce training costs
•Speed and error rates are relative to cost
•Speed of performance is important because of the number of
transactions
•Subjective satisfaction is fairly importantto limit operator
burnout

12. Usability Motivation (Cont)
Consumer electronics, e-commerce, and social media
•The transformative power of consumer electronics has been celebrated
by those who see improved family communication, better healthcare,
thriving , businesses, and wider access to education.
•The social media applications and user-generated content have
become part of daily life for many users.
•Ease of learning, low error rates, and subjective satisfaction are
paramount because use is discretionary and competition is fierce. If the
users cannot succeed quickly, they will give up or try a competing
supplier.
•Critics raise concerns about reduced privacy, dangers in distracted
driving, and decline quality of interpersonal relationships.

13. Usability
Motivation
(Cont
)
HomeandEntertainment Application
•Word processing, electronic mail, computer conferencing, and video game
systems, educational packages, search engines, mobile device, etc.
•Ease of learning, low error rates, and subjective satisfaction are paramount
due to use is often discretionary and competition fierce
•Infrequent use of some applications means interfaces must be intuitive and
easy to use online help is important
•Choosing functionality is difficult because the population has a wide range of
both novice and expert users
•Solution: alayered or level-structured design
•Competition cause the need for low cost
•Another approach to winning novice users is to carefully trim the features to
make a simple device or application so users can get star ted easily.

14. Usability Motivation (Cont)
Exploratory, CreativeandCollaborativeInterfaces
•Exploratory applications: web browsers, search engines, data visualization, and team
collaboration support.
•Creative applications: design environments, music-composition tools, animation builders, and
video-editing systems.
•Collaborative interfaces enable two or more people to work together through many features
•The users may be knowledgeable in the task domains but novices in the underlying computer
concepts: often high motivation and high expectation
•Designers can pursue the goal of having the computer “vanish” as users become completely
absorbed
•DifficultBenchmarks are hard to describe for exploratory tasks and device users
•With these applications, the computer shouldbe transparent so that the user can be absorbed
in their task domain
•Itprovidesa direct-manipulation representation of the world of action, supplemented by
keyboard shortcuts, tasks are carried out by rapid familiarselections or gestures

15. Usability Motivation (Cont)
Social–TechnicalSystem
•Complex systems that involve many people over long
time periods,
e.gVoting, health support, identity verification, crime
reportingsystem
•Trust, privacy, responsibility, and security are issues
•Verifiable sources and status feedback are important
•Ease of learning for novices and feedback to build trust
•Administrators need tools to detect unusual patterns of
usageorfraud

16. Universal Usability
•Understanding the physical, intellectual, and personality
differences between users is vital for expanding market
share, supportingrequired government services, and
enabling creative participation by the broadest possible set
of users
•Variationin physicalabilitiesandphysicalworkplaces
•Diversecognitiveandperceptualabilities
•Personalitydifferences
•Culturalandinternationaldiversity
•Userwithdisabilities
•Age diversity

17. Variation in
physical
abilities and
physical
workplaces
•Basic data about human dimensions comes
from research in anthropometry
•There is no average user, either
compromises must be madeor multiple
versions of a system must be created
•Physical measurement of human dimensions
are not enough, take into accountdynamic
measures such as reach, strength or speed

18. Variationin
physical
abilitiesand
physical
workplaces
(Cont)
•Screen-brightness preferences vary substantially, designers
customarily provide a knob to enable user control
•Account for variances of the user population's sense
perception
•Vision: depth, contrast, color blindness, and motion
sensitivity
•Touch: keyboard and touch screen sensitivity
•Hearing: audio clues must be distinct
•Workplace design can both help and hinder work
performance

19. Variation in
physical
abilities and
physical
workplaces
(Cont)
•The standard ANSI/HFES 100-2007 Human
Factors Engineering of Computer Workstations
(2007) lists these concerns:
•Work-surface and display-support height
•Clearance under work surface for legs
•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 support
•Availability of armrests, footrests, and palmrests

20. Diverse Cognitive & Perceptual Abilities
•The human ability to interpret sensory input rapidly and to initiate complex actions makes
modern computer systems possible
•The journal Ergonomics Abstractsoffers 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

21. Diverse Cognitive & Perceptual Abilities (Cont)
•They also suggest this set of factors affecting perceptual and motor performance:
•Arousal and vigilance
•Fatigue and sleep deprivation
•Perceptual (mental) load
•Knowledge of results and feedback
•Monotony and boredom
•Sensory deprivation
•Nutrition and diet
•Fear, anxiety, mood, and emotion
•Drugs, smoking, and alcohol
•Physiological rhythms
•But note, in any application, background experience and knowledge in the task domain and the interface domain play key roles in learning and performance

22. Personality Differences
•There is no set taxonomy for identifying user personality types
•Designers must be aware that populations are subdivided and that these
subdivisions have various responses to different stimuli
•Myers-Briggs Type Indicator (MBTI)
•extroversion versus introversion
•sensing versus intuition
•perceptive versus judging
•feeling versus thinking

23. Cultural &InternationalDiversity
•User-interface design concerns for:
•Characters, numerals, special characters, and diacriticals
•Left-to-right versus right-to-left versus vertical input and reading
•Date and time formats
•Numeric and currency formats
•Weights and measures
•Telephone numbers and addresses
•Names and titles (Mr., Ms., Mme.)
•Social-security, national identification, and passport numbers
•Capitalization and punctuation
•Sorting sequences
•Icons, buttons, colors
•Pluralization, grammar, spelling
•Etiquette, policies, tone, formality, metaphors
•The current highly competitive atmosphere means that more effective localization may produce a strong advantage

24. Users with PhysicalChallenges
•Designers must plan early to accommodate users with disabilities
•Early planning is more cost efficient than adding on later
•Businesses must comply with the "Americans With Disabilities" Act for
some applications

25. Younger UsersOlderAdultUsers
•Including the elderly is fairly easy
•Designers should allow for variability
within their applications via settings
for sound, color, brightness, font sizes,
etc. with less distracting animation

26. USER
EXPERIENCE

27. The User Experience
•How a product behaves and is used by people in the real world
•“every product that is used by someone has a user experience: newspapers, ketchup bottles, reclining armchairs, cardigan sweaters.” (Garrett, 2003)
•“the way people feel about it and their pleasure and satisfaction when using it, looking at it, holding it, and opening or closing it. It includes their overall impression of how good it is to use, right down to the sensual effect small details have on them, such as how smoothly a switch rotates or the sound of a click and the touch of a button when pressing it. An impor-tant aspect is the quality of the experience someone has, be it a quick one, such as taking a photo; a leisurely one, such as playing with an interactive toy; or an integrated one, such as visiting a museum” (Law et al., 2009).
•Cannot design a user experience, only design fora user experience

28. Defining user experience
How users perceive a product, such as whether a smartwatch
is seen as sleek or chunky, and their emotional reaction to it,
such as whether people have a positive experience when
using it.
(Hornbæk and Hertzum, 2017)
Hassenzahl’s(2010) model of the user experience
•Pragmatic: how simple, practical, and obvious it is for
the user to achieve their goals
•Hedonic: how evocative and stimulating the interaction
is to users

29. User Experience Goals
Desirable Aspects
Satisfying Helpful
Enjoyable Motivating
Engaging Challenging
Pleasurable Enhancing sociability
Exciting Supporting creativity
Entertaining Cognitively stimulating
Fun Rewarding
Provocative Emotionally fulfilling
Surprising Experiencing flow
Undesirable Aspects
Boring
Frustrating
Making one feel guilty
Annoying
Childish
Unpleasant
Patronizing
Making one feel stupid
Cutesy
Gimmicky
VS

30. What makes
a great user
experience?
•User experience is different for
everyone.
•Remember!!
•Though you have designed the product, you
might not be a potential user who might be
using the product.
•Hencewe cannot assume what a user wants
or How they need.
•Doauserresearch
•UXDesignProcess:
•You can not jump straight to the solution

31. Usability and user experience goals
•Selecting terms to convey a person’s feelings, emotions, etc., can help
designers understand the multifaceted nature of the user experience
•How do usability goals differ from user experience goals?
•Are there trade-offs between the two kinds of goals?
•e.g. can a product be both fun and safe?
•How easy is it to measure usability versus user experience goals?