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INFO3315 HCI
Human-Computer InteractionIntroduction
Part 2
What is HCI?Why does it matter?
What is it? What will you be doing this semester? Where is the technology?
The user interface was once the last part of a system to be designed. Now it is the first. It is recognized as being primary because, to novices and
professionals alike, what is presented to one’s senses is one’s computer.
Kay, A. (1984). Computer software. Scientific American, 251(3), 41-47.
Exercise
• What is the cost of a minor usability error in a large organisation? eg. – 5000 employees, – task done 10 times on average working day– Mean time to complete is 1 minute, compared to
ideal of 10 seconds– About 10% of the time, people get stuck and take
10 minutes or more, have to ask for help, become frustrated, give poor service……
IntroductionWhat is usability?
What isn’t it?What will you be aiming to achieve?
How does the text present this?
Hartson and Pyla: 1.3: From usability to user experience
1.3.1-5, pp 9-12, 1.3.9 pp 19-21
What is usability?
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What is “Usability”?
• ISO standards……• Learnability• Efficiency• Memorability• Errors• Satisfaction
• Performance• Affect
© 2013 - Brad Myers
What is usability?
• “Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• Satisfaction: How pleasant is it to use the design?”Usability 101: Introduction to Usabilityby Jakob Nielsen on January 4, 2012 http://www.nngroup.com/articles/usability-101-introduction-to-usability/
Is there more than usability?
Utility • Usability and utility are equally important and together determine
whether something is useful” – Easy but useless?– Hard, but potentially valuable?
• “Definition: Utility = whether it provides the features you need.• Definition: Usability = how easy & pleasant these features are to
use.• Definition: Useful = usability + utility.”
Usability 101: Introduction to Usabilityby Jakob Nielsen on January 4, 2012 http://www.nngroup.com/articles/usability-101-introduction-to-usability/
User “Experience” (UX)• Even more than “usability”
– Usability focuses on performance
• User Experience– Emotion, Heritage– Fun, Style, Art– Branding, Reputation– Political, social personal connections– Beyond just the device itself – “Service Design”
• Blends: usability engineering, software engineering, ergonomics, hardware engineering, marketing, graphic design
11© 2013 - Brad Myers
12www.id-book.com
User experience goalsDesirable aspectssatisfying helpful funenjoyable motivating provocativeengaging challenging surprisingpleasurable enhancing sociability rewardingexciting supporting creativity emotionally fulfillingentertaining cognitively stimulating
Undesirable aspectsboring unpleasantfrustrating patronizingmaking one feel guilty making one feel stupidannoying cutesychildish gimmicky
This is a visceral response
What makes it hard to create usable interfaces that provide a delightful user experience?
It is hard to think like the users
• May need to understand the domain• And the context of use• And what the user knows• And what they have experienced• And how they will interpret the interface
elements, what they will “see”
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Specifications are always wrong
"Only slightly more than 30% of the code developed in application software development ever gets used as intended by end-users. The reason for this statistic may be a result of developers not understanding what their users need."
-- Hugh Beyer and Karen Holtzblatt, "Contextual Design: A Customer-Centric Approach to Systems Design,“
ACM Interactions, Sep+Oct, 1997, iv.5, p. 62.
Need for prototyping and iteration
© 2013 - Brad Myers
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More reasons why it is difficult….• Tasks and domains are complex
– Word 1 (100 commands) vs. Word 2013 (>2000)– MacDraw 1 vs. Illustrator – BMW iDrive adjusts over 700 functions
• Existing theories and guidelines are not sufficient – Too specific and/or too general – Standard does not address all issues.
• Adding graphics can make worse– Pretty Easy to use
• Can’t just copy other designs– Legal issues
© 2013 - Brad Myers
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More reasons why it is difficult….
• All UI design involves tradeoffs: – Standards (style guides, related products) – Graphic design (artistic) – Technical writing (Documentation) – Internationalization – Performance– Multiple platforms (hardware, browsers, etc.)– High-level and low-level details– External factors (social issues) – Legal issues – Time to develop and test (“time to market”)
© 2013 - Brad Myers
Misconceptions about usability
• “Doing usability” sometimes thought of as equivalent to usability testing– Diagnostic view
• Or sometimes usability is seen to be about dressing it up– “After the software is built, I want the usability
people to make it look pretty”
19Copyright MKP. All rights reserved.
Interaction design is not about software
20Copyright MKP. All rights reserved.
Interaction component: How a UI works, it’s “look
and feel” and behavior
UI software component: Code
that implements the interaction
component
Two distinct roles
• Interaction designer and UI software designer
• Premise: Describing interaction from user’s view should result in more usable design than describing it from software or programmer view
• Inherent conflict of interest: What’s best for the user is seldom easiest for the software developer!
21Copyright MKP. All rights reserved.
Objectives of this course
• Applying a usability engineering life cycle
– Contextual inquiry and analysis
– Requirements extraction and design-informing models
– Conceptual and detailed design
– Iterative prototyping and evaluation
• Understanding and applying interaction design guidelines
22Copyright MKP. All rights reserved.
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Why are User Interfaces Difficult to Implement?
© 2013 - Brad Myers
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Why Are User Interfaces Hard to Implement?
• They are hard to design, requiring iterative implementation– Not the waterfall model: specify, design, implement, test,
deliver
• They are reactive and are programmed from the "inside-out" – Event based programming – More difficult to modularize
© 2013 - Brad Myers
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Why Hard to Implement? cont.
• They generally require multi-processing – To deal with user typing; aborts – Window refresh – Window system as a different process – Multiple input devices
• There are real-time requirements for handling input events – Output 60 times a second – Keep up with mouse tracking – Video, sound, multi-media
© 2013 - Brad Myers
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Why Hard to Implement? cont.
• Need for robustness – No crashing, on any input – Helpful error messages and recover gracefully – Aborts – Undo
• Lower testability – Few tools for regression testing
© 2013 - Brad Myers
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Why Hard to Implement? cont.
• Little language support – Primitives in computer languages make bad user interfaces – Enormous, complex libraries – Features like object-oriented, constraints, multi-processing
• Complexity of the tools – Full bookshelf for documentation of user interface frameworks– MFC, Java Swing, VB .Net, etc.
• Difficulty of Modularization
© 2013 - Brad Myers
Overview of the approach
H&P Chapter 2: The Wheel2.2,pp53-5
H&P Chapter 2, p53
H&P Chapter 2, p54
HCI mattersand is hard to do well…
• In general, interfaces are a very large part of effort of system• Financial impact
– Make or break• Creating good user experiences with systems is hard achieve• Major lessons:
– 1: You cannot rely on intuition– 2: HCI techniques can really help– 3: Hard work, using established techniques, is the secret (not
brilliant insight by the gifted lazy)– 4: Iterative nature of creating interfaces