Digital Marketing (DMK201 at ) - Lecture 7: Website Planning and Usability
Usability with Project Lecture 10 – 19/03/10
description
Transcript of Usability with Project Lecture 10 – 19/03/10
© Simeon Keates 2010
Usability with ProjectLecture 10 – 19/03/10Dr. Simeon Keates
© Simeon Keates 2010
Exercise – part 1
Consider sending an SMS or e-mail Look at one of your mobile phones … And a laptop, etc.
Perform exclusion calculations on each product using the data on:• http://www.eng.cam.ac.uk/inclusivedesign/
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Exercise – part 2
Identify the common methods of interacting with the product
Identify which of the 7 DFS capability scales are involved in the interaction
Based on the DFS scales, estimate the limiting capability demand for each scale
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Exercise – part 3
Report the number and %age of people excluded by each capability demand• For 16+ and 75+
Report the total number and %age of people excluded by the product• For 16+ and 75+
Prepare a 5 minute presentation to discuss:• Your exclusion calculation assumptions• Your exclusion calculation results• What were the principal causes of exclusion?• What do you think should be done to reduce the exclusion for each product?
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Assessment of DTT STBs...
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A systems overview
User
Remotecontrol
Service provider
Television
Remotecontrol
Set top box (STB)
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Motivations for study
Commissioned by UK Department of Trade and Industry Wanted to find out who could not access DTT Original focus on ‘the disabled’ Definition broadened...
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Why?
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Typical assessment methods used in this research
Expert assessment
Exclusion analysis
User observation
Questionnaires
Interviews
Focus Groups
Assessment of STBs
Customer expectations
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Methodology - Choice of STBs
2 STBs chosen for study STB1 - marketed as “easy to use” STB2 - market leader
1 digital satellite system chose as comparison STB3 – developed by content provider
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Expert assessment
4 assessors 2 with DTV experience, 2 without STB protocol only Aims to identify most likely sources of problems• Define protocol for following assessments
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Methodology - Analogue TV protocol
6 activities• Switch on• Change channel• Change volume• Teletext (find local weather)• Subtitles (on/off)• Switch off
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Methodology - STB protocol
8 activities• Installation• Switch on• Change channels (direct + EPG)• Change volume• Teletext (find local weather)• Subtitles (on/off)• BBCi (find local weather)• Switch off
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Expert Assessment - Results
13 major sources of difficulty found 4 – Installation and set-up• e.g. instruction manual, initial tuning
5 – Operation • e.g. multiple modes, subtitles
4 – Remote controls• e.g. labelling, layout
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Exclusion analysis
Systematic analysis Combined with data from Office of National Statistics• Population data 1996/7 UK Disability Follow-Up Survey
Aims to calculate how many people have the difficulties highlighted by expert assessment• How many people in the user observation should have those difficulties?
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Example – breakdown of installationHigh-level activities Medium-level activitiesUnpack STB cut through outer packaging, open box, pick
up contents, put down contents, find and recognise instructions
Follow instructions open and hold instructions, read instructions, understand instructions
Plan cable connections (what goes where) match box contents to instructions, identify AV components (e.g. VCR, TV, amplifier, speakers) and cables, plan signal flow, identify cables to be moved
Move components to get access to cable slots grip components, pull forward
Disconnect cables to be moved identify cables, grip and pull them
Place STB near AV components pick up and carry STB, put it down
Connect cables in correct order identify cables, identify cable sockets, pick up cables, connect them
Replace AV components to usual position grip components, push back
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Exclusion analysis - Results
25
20
15
10
5
0Analogue DTV Analogue DTV
16+ 75+
Pop
ulat
ion
(,000
s)
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Exclusion analysis - Results
25
20
15
10
5
0
25
20
15
10
5
0Analogue DTV Analogue DTV
16+ 75+
Pop
ulat
ion
(,000
s)P
opulation(%
age)
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User observations - Overview
13 users - 12 aged 60+, 1 aged 24• 9 no DTV experience• 2 owned STBs• 1 owned satellite box• 1 owned iDTV• 7 PC users, 6 non-users
All ‘independent’ living
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User observations - Methodology
2 hour sessions comprising: 30 minutes briefing 60-75 minutes with equipment• 15-20 minutes analogue• 40-60 minutes DTV• 2 STBs
15 minutes debriefing
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User observations - Set-up
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User observations - Example visual problems
Finding buttons on r/c • Especially POWER
Switching between r/c and screen• Different pairs of glasses
Reading on-screen font • No zoom facility
Reading instruction manual• Small print
New difficulty
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User observations - Example motor problems
Pressing buttons on r/c
• Size and shape
Time-outs
• e.g. on EPG (040 -> 004)
Arrow button overshoot
• Oscillating cursor
New difficulty
New difficulty
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STB2 remote control
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STB1 remote control
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User observations - Example ‘cognitive’ problems
Use of OK/SELECT Inconsistent language (OK=SELECT?) Which r/c to use / which mode am I in? How to start/navigate BBCi/Teletext? How to call up/navigate on-screen menus? How to operate/navigate the EPG? Inconsistent layout • e.g. LHS on screen, RHS on r/c
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User observations - Summary of results
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Summary
Cognitive/experience issues most important
Many of the problems easily avoidable
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Origins of the problems for older users
New language / terminology • Jargon
New input paradigms• Part TV, part PC
New interaction concept• Interacting with STB, not TV
Inadequate explanationClassic case of
“designers designing for themselves”
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Implications of prevalence of cognitive difficulties
What does this mean for assessment methods?• Single assessment methods vs. multiple?• In what order should they be used?
What does this mean for designers?• How to design for different experience?
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What is “reasonable accommodation”?
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Defining “reasonable accommodation”
Must offer “reasonable accommodation”• BUT what is reasonable?
Not defined explicitly• Companies left guessing
Will be defined in courts• Major risk/headache for companies
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Attitudes to “reasonable accommodation”
EQUITABLE ACCESS
MINIMUM(compliance)
Access to functionality
IDEALAccess to
functionalityin same time
EQUITABLE ACCESS
MINIMUM(compliance)
Access to functionality
IDEALAccess to
functionalityin same timeIDEOLOGICAL
DIVIDE
Prag
mat
ists
Idea
lists
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Interesting questions for companies
Is the equitable access ideal possible?• Is the equitable access minimum possible?• “ Equal, but different ” problem
Users with functional impairments => longer times
Can technology always make up the difference in user capabilities?
3 case studies…
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Case study 1: The personal information point
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The information point accessibility assessment
Sensory assessment: Screen too high and not adjustable Audio output not duplicated Visual output not duplicated
Motor assessment: Need to stand Reaching and dexterity demands
53% of target users excluded
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Case study 2 – Cursor assistance for motor-impaired users
Symptoms that can affect cursor control:
Tremor Spasm Restricted motion Reduced strength Poor co-ordination
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User group behaviours
0
0.5
1
1.5
2
2.5
3
3.5
Group OA Group P Group Y Group A
0
20
40
60
80
100
120
Group OA Group P Group Y Group A
Target activation times
Peak velocities
No. of incorrect clicks
0
1
2
3
4
5
Group OA Group P Group Y Group A
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Summarising the differences
Younger adults (IBM interns)• Shortest (1), fastest (1), more errors (3) - slapdash
• “I can fix it”• Games culture?
Adults (IBM regulars)• Shorter (2), faster (2), fewest errors (1)
• Best compromise between speed and accuracy? Parkinson’s users• Longer (3), slowest (4), fewer errors (2)
• Slow, but sure Older adults• Longest (4), slower (3), most errors (4)
• Vision difficulties?• Lack of experience
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A method of cursor assistance
Haptic gravity wells:
Target
Gravity well
Attractive force
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Experimental set-up
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The effect of gravity wells
Target
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Motor impairment in practice…
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Results - Throughput
0
2
4
6
8
10
MI AB
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Case study 2 summary
Haptic gravity wells are clearly very helpful MI users “with” on similar level to AB users “without”
BUT: AB users also improve “with” Is this “equal” time? Is this “reasonable”???
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Case study 3 – Paperless office
AN Other wants to move to a paperless office• Currently receives 3.5 million pages per day
Paper documents are stored as TIFFs
Section 508 accessibility requirements• Sight-impaired• Low vision
Current solution – employ readers• “ Equal, but different. ”• Is this reasonable?
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The study documents
Almost fully unconstrained Content:• Unconstrained vocabulary
Text:• Typed• Handwritten• Annotated• Stamps
Graphical content:• Diagrams• Charts • Graphs
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Examples of the study documents
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Examples of the study documents (cont.)
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Examples of the study documents (cont.)
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Readability metrics (text)
Translation rates:• Character-by-character• Word-by-word
Number and %ages of errors:• Level 1 - Minor• Level 2 - Moderate• Level 3 - Serious
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TIFF file
OCR – The scanning process..................................11111.........11...11.......11.....11......11.....11.............11..........11111........111..11.......11....11......11.....11......11.....11......11....111......111..1.11.1.....1111..111..................
111
1
1
1
11 11
11
1
11
1111
11
1
111 1111
11 1
11
1
1 111
11
111 1
11 1
1
111111 1
1 1
1
1
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OCR – Possible sources of scanning errors
Data LOSS NOISE
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Comparing three OCR engines
“…also develop the skills to invert containers to get objects *inside. He should begin to find small details in a favorite picture book (a bird in a *tree, a small fish in the *ocean). His understanding of familiar objects should…”
FineReader:
“…*also *develop *the *skills *to *irxvert *containers *to *get *ob^ects *inside. *?e *should *begin *to *Znd *small *details *i? *a favorite *picture *baa? *?a *bird *in *a *true, *a *small *ash *in *the *ocean}. *his *understanding *of *familiar *ob^ects *should…”
OmniPage:
“…*also *de???op *the *s?il?s *ta *ivart?an#ainer?to *e?ob??cts?n?id?. *?e *shau?ti *b?ta *Znd *srnali *details *i?a *favarita *picture *baa??bi?rd *in *a *tra?,a *srr?a????in *tk?e *o?ean}. *?is *und?rt?a?af *fa.?i?iar *ob?ects *hau?d *co??i?u?ta *de?eiap *d?i?houi d…”
Recognita:
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OCR results – Calculating the error rates
Record the document properties• # of words, characters• Font types (e.g. typed, handwritten) and sizes
Count instances of error types• Redaction errors• Spaces +ed, -ed• Format errors (e.g. wrong case, incorrect text positioning)• Extraction errors (i.e. incorrect translation)
• By character• By word
Classify severity• Level 1 – minor• Level 2 – moderate• Level 3 – severe
Calculate %age error rates
Note: classification for sighted users
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OCR results – Overall word error % rates
Typed page 6.50 %(1 word in 15)
Typed page with notes
8.12 %(1 word in 12)
Faxes 14.45 %(1 word in 7)
Pictures and graphs
23.45 %(1 word in 4)
Handwritten reports
36.35 %(1 word in 3)
EKGs 49.72 %(1 word in 2)
A “typical sentence” contains 7 words.
An extraction error rate of 6.5% equates to 1 word error every 2 sentences.
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Conclusions of OCR investigation
“ Current OCR technology is not capable of providing an acceptable level of text extraction from medical evidence as it is now received. ”
“ Technology cannot provide equitable access in this case. Alternative methods are required. ”
“ Equal, but different. ”
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Overall summary
Some products clearly not “reasonable”• Case study 1
Technology cannot always make up for lack of user capability• Case study 2• Even when it does – the goalposts move!!!
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Conclusion
What is needed is a framework for evaluating “reasonableness”
Based on quantifiable metrics
Reliable, repeatable, consistent, robust
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Designing for cognitive support
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Background
International Symposium• Held in October 2005• Venue: IBM TJ Watson Research Center• Sponsored by: IBM HA & AC• 10 invited experts
Data presented here from that Symposium
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Defining C&LDs
US medical community definition• “A cognitive disability arises from an impairment that affects IQ”• i.e. effects capability to acquire, process and utilise knowledge• Arises from how medical conditions are diagnosed and treated
Educators focus on learning difficulties• Often focused on educational attainment
Do behavioural difficulties count?• Some say yes, some say no
No single, clear definition. Mostly focused on what users cannot do
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Defining C&LDs for UI design
Alternative definition needed for UI design• Need to understand what users are capable of• Not what they cannot do
Need functional descriptions of capabilities Descriptions tailored to design project
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Prevalence of C&LDs - US statistics
When asked • “Have you had a physical, mental or emotional condition lasting 6 months or
more that made it difficult to learn, remember or concentrate” 5.2% of all US adults agreed• (Source: 1999-2004 American Community Survey)
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Prevalence of C&LDs - GB statistics
5.6% of GB adults self-report some form of cognitive impairment• (Source: 1996 Disability Follow-Up Survey)
“Cognitive impairment” comprised of:• Communication
• E.g. “Has some difficulty understanding what other people say or what they mean”• Intellectual Functioning
• E.g. “Often forgets what was supposed to be doing in the middle of something”
Figures from both surveys are most likely conservative
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Role of cognition in interaction
Model Human Processor (Card, Moran and Newell)
F(t) = xp + yc + zm
where
• p = perceptual time unit
• c = cognitive time unit
• m = motor function time unit• x, y, z are integers
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Role of cognition (cont.) - Simplex II
“Cognition” comprises:• Working memory• Emotions and drives• Perception• Output• Feedback• Complex output sequences• Cognitive models• Long-term memory• Executive functions(Adams)
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Why C&LDs are not commonly addressed in UA…
They are often difficult to diagnose• Perception issues are easy to diagnose, cognitive ones are not
Many do not have a “universal” diagnosis• E.g. what exactly is dyslexia?
Many people with them are reluctant to admit this• The “invisible” impairment - stigma
Designing for them is not easy• No clear description of C&LD makes design more difficult
Can be assisted by “design best practices”
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1 - Involve users in design process
“Standard” UA advice Can act as design partners• Working with designers
User study participants• Issues regarding ethical approval
The more designers know about their users, the better their designs become
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2 - Find required set of demands to complete the task
Every task has associated capability demands• Writing a letter, using an ATM, etc.
Every IT system has associated capability demands• Navigation, interaction, etc.
Designers should ensure that IT system demands are no more than the task demands
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3 - Use scaffolding techniques
New concepts need to be supported in multiple ways
New
concept
Existing
concept
New
concept
Existing
concept
Existing
concept
Existing
concept
The more references to existing knowledge, the more stable the new knowledge
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4 - Use positive reinforcement
Many people with C&LD have low self-esteem• Perceived stigma• Often branded as “failures” or “thick” as children• Are used to being “judged”
IT is attractive because it is not so quick to “label”• Designers need to build on this perception• Avoid negative comments• Provide positive support and reinforcement
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5 - Design for user’s learning strengths
Not everyone has uniform C&LDs Need to design to user strengths, e.g. …
Older adults • often have poor “dynamic” memory• often have good “crystalline” memory
People with dyslexia• written instructions hard to follow• visual / auditory instructions easy to follow
Relate new concepts to familiar ones
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Use multiple modalities
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6 - Design for flexibility
E.g.: Offer sliding scales of complexity
Save Print
File Edit Format
File Edit View Insert Format Tools
Basic word processor
Mid-level word processor
High-level word processor
Allow users to proceed at their own pace
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6 - Design for flexibility
E.g.: Offer sliding scales of complexity
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7 - Chunk information
Difficult:• “The 2007 Jeep Grand Cherokee Overland has a 5.7L Hemi engine that
develops 330 BHP. It’s a willing a responsive engine. Prices for this model start at around $37,000 and go up to $44,000 for a fully specced up version.”
Better:• Model: Jeep Grand Cherokee Overland• Engine: 5.7L Hemi• Price: $37,000 - $44,000
Small bits of knowledge at a time
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8 - Keep hierarchy depths to a minimum
As a general rule, depths should be <3
is better than:
Breadth, not depth
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Potential conflict with motor/sensory issues
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9 - Recognise the use of coping strategies
Try to complement, support or augment these
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Other best practices - I
Use clear language• Avoid jargon
Provide appropriate “help” functionality• Concrete, repeatable, focused and consistent
Present assistance options carefully• Make sure to avoid “stigma”
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Other best practices - II
Avoid “feature creep”• Difficult for older users who rely on crystalline memory
Try to be consistent• Consistent methods of exiting, for example
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Summary
Cognitive and learning difficulties are the “invisible” impairment They are widespread (c. 5% of the population) They affect how well users can interact with UIs But receive comparatively little research and design attention
Need more attention!
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For further details
ACM SIGACCESS Newsletter:• September 2005 Number 83• http://www.acm.org/sigaccess/newsletter/sept05.php
International Journal on UA in the Information Society• Volume 5, Number 4, April, 2007
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Exercise
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Exercise – part 1
Finish making changes to your site
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