© simeon keates 2009 usability with project lecture 10 – 09/10/09 dr. simeon keates

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© Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

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Page 1: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Usability with ProjectLecture 10 – 09/10/09Dr. Simeon Keates

Page 2: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Exercise – part 1

Consider sending an SMS or e-mail Look at one of your mobile phones … And a laptop

Also, look at one of the remote controls you will be loaned!!! [Note – I need these back!!!]

Perform exclusion calculations on each product using the data on:• http://www.eng.cam.ac.uk/inclusivedesign/

Page 2

Page 3: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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

Page 3

Page 4: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 5: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Implementing accessibility

Page 5

Page 6: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Existing “accessibility” standards

Buildings access• e.g. BS8300:2001 Design of buildings and their approaches to meet the needs of

disabled people Assistive Technology • e.g. ISO 9999:2002 Technical aids for persons with disabilities – Classification and

terminology Anthropometrics • e.g. BS4467:1997 Guide to dimensions in designing for elderly people

Medical device standards• e.g. ISO 13485 / ISO 13488 – Quality systems for medical devices

Standards development • e.g. PD ISO/IEC Guide 71 Guidelines for standards developers to address the needs

of older persons and persons with disabilities

Page 6

Page 7: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

The BS7000 series – Guides to managing…

Part 1 – … innovation Part 2 – … the design of manufactured products Part 3 – … service design Part 4 – … design in construction Part 5 – … obsolescence Part 6 – … inclusive design Part 10 – Glossary of terms used in design

management

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Page 8: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Inside BS7000-6 – the definition of inclusive design

[The] design of mainstream products … that are accessible to, and usable by, as many people as reasonably possible on a global basis, in a wide variety of situations and to the greatest extent possible without the need for special adaptation or specialized design.

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Page 9: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Inside BS7000-6 – product options

Complete integrated range without need for adaptive accessories

New models added to range, plus adaptive accessories for existing models

Complementary range, co-ordinated with existing range to some degree

Separate range, unconnected with mainstream offer

Decreasingpreference

Page 9

Page 10: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Key aspects of BS7000-6

Role of inclusive design ‘champions’ formalised• Previously “unofficial” champions

Board-level responsibility enforced

Rigorous ‘gateways’ in design process• Independent of design methodology adopted

All user exclusions have to be explained…

… and ‘justified’• Leads to paper trail• Potential basis for legal defence

Page 10

Page 11: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Implementing accessibility - Summary

Design for accessibility is important for industry

Adopting design for accessibility practices requires a plan. It does not just happen overnight; it needs a strategic approach

Design for accessibility affects all levels of the corporate hierarchy within a company

Page 11

Page 12: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

The role of senior management

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Page 13: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 1 – Scoping the business plan

Stage 1.1 – Assigning responsibility• Suggested outcome – a named top manager to champion and have explicit

responsibility for design for accessibility.

Stage 1.2 – Acquiring basic knowledge• Suggested outcome – a common understanding of the basic aims and

principles of design for accessibility.

Stage 1.3 – Understanding the current situation• Suggested outcome – a completed audit of the company’s entire or selected

product lines.

Stage 1.4 – Formulating a plan of action• Suggested outcome – an initial plan of action for the implementation of

design for accessibility.

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Page 14: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 2 – Shaping the business plan

Stage 2.1 – Communicate design for accessibility intent• Suggested outcome – a mission statement that clearly communicates how

important design for accessibility is for the company.

Stage 2.2 – Define corporate philosophy• Suggested outcome – a design for accessibility “bible” outlining corporate

philosophy and preferred language.

Stage 2.3 – Identify specific objectives to be achieved• Suggested outcome – a master program of clearly stated initial corporate

objectives with an identified time-line for completion.

Stage 2.4 – Promote design for accessibility across the company• Suggested outcome – a structured program for communicating the

importance, benefits and opportunities of design for accessibility throughout the workforce.

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Page 15: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 3 – Implementing the business plan

Stage 3.1 – Implement management structures for design for accessibility• Suggested outcome – a clearly defined management structure put in place.

Stage 3.2 – Perform pilot studies• Suggested outcome – analysed results from pilot studies that clearly identify

successes and lessons to be learned.

Stage 3.3 – Recognize and enhance expertise• Suggested outcome – a corporate map of teams and individuals with design

for accessibility expertise and a plan for increasing overall corporate expertise.

Stage 3.4 – Review progress• Suggested outcome – a review of progress made to date and

recommendations for further improvements in the implementation of design for accessibility.

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Page 16: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 4 – Selling accessibility

Stage 4.1 – Identify and leverage competitive advantages• Suggested outcome – a structured plan to transfer the successes in design

for accessibility throughout the company products range and brands.

Stage 4.2 – Identify opportunities for improved corporate image• Suggested outcome – a structured marketing plan for communicating the

new corporate and brand image.

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Page 17: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 5 – Reviewing and refining business plan

Stage 5.1 – Recognize and reward successes• Suggested outcome – a reward program that recognizes and encourages

innovation.

Stage 5.2 – Review and refine design for accessibility approach• Suggested outcome – a completely realized infrastructure for managing and

implementing design for accessibility.

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Page 18: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

The role of senior management - Summary

Top management plays a pivotal role in implementing design for accessibility practices and a continuing role in maintaining design for accessibility practices

Top management initiates and drives the initial adoption of design for accessibility and retains ultimate responsibility for the success of design for accessibility

Top management shapes the company’s design for accessibility philosophy and is responsible for communicating this throughout the company and ensuring that corporate targets for product accessibility are met.

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Page 19: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Project management

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Page 20: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 1 – Define project

Stage 1.1 – Initial research• Suggested outcome – a description of the opportunity.

Stage 1.2 – Develop design brief• Suggested outcome – a design brief that states the general objectives and

requirements of the project.

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Page 21: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 2 – Design, detail and implement solution

Stage 2.1 – Generation of solution concepts• Suggested outcome – a range of potential alternative solutions that meet the

design brief.

Stage 2.2 – Selection and refinement of most effective solution• Suggested outcome – a solution that meets the design brief most effectively.

Stage 2.3 – Detail design of solution• Suggested outcome – a detailed design of the chosen solution.

Stage 2.4 – Ready solution for production• Suggested outcome – a production-ready solution.

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Page 22: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 3 – Go to market

Stage 3.1 – Launch of product in marketplace• Suggested outcome – a carefully planned and executed launch strategy.

Stage 3.2 – Evolution of product• Suggested outcome – a series of product updates and augmentations based

on customer and market feedback.

Stage 3.3 – Extension of product range• Suggested outcome – a series of new or modified products to complement

and build on the success of the original product.

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Page 23: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Phase 4 - Project closure

Stage 4.1 – Decommissioning of product • Suggested outcome – a carefully planned and executed market withdrawal

strategy.

Stage 4.2 – Final review and lessons learned• Suggested outcome – a comprehensive final review of all aspects of the full

life of the product with clearly identified successes and lessons to be learned.

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Page 24: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Project management - Summary

Project managers must embrace the concept of design for accessibility if it is to be implemented successfully within the company

Project managers are responsible for ensuring that the design team meets the design for accessibility targets set by senior management

Document everything. Written records of why particular decisions were taken are the basis of an invaluable knowledge resource

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Page 25: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

What is “reasonable accommodation”?

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Page 26: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 27: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 28: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 29: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Case study 1: The personal information point

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Page 30: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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

Is this “reasonable”?

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Page 31: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 32: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 33: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 34: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

A method of cursor assistance

Haptic gravity wells:

Target

Gravity well

Attractive force

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Page 35: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Experimental set-up

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Page 36: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

The effect of gravity wells

Target

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Page 37: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Motor impairment in practice…

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Page 38: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Results - Throughput

0

2

4

6

8

10

MI AB

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Page 39: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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”???

Page 39

Page 40: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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?

Page 40

Page 41: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

The study documents

Almost fully unconstrained Content:• Unconstrained vocabulary

Text:• Typed• Handwritten• Annotated• Stamps

Graphical content:• Diagrams• Charts • Graphs

Page 41

Page 42: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Examples of the study documents

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Page 43: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Examples of the study documents (cont.)

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Page 44: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Examples of the study documents (cont.)

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Page 45: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 46: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 47: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

OCR – Possible sources of scanning errors

Data LOSS NOISE

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Page 48: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 49: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 50: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

OCR results – An example extracted document – 1

Extracted text:

*evaluators, shQWfag’an interest in imitating words *and sp *eech.^j^kd real words along^vith j argon to exjgpss. himself . *dflffVily indicated that they understand most of what tie *says.^H^^owedhisuse of two+ word phrases

Original text:

[Typed page document]

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Page 51: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

OCR results – An example extracted document – 2

Extracted text:

*IBISES6?? *fc?day *?P *a *yearly *SJn *exam’ *She *is *a *40 *^ear *old *white *feraale status post ^aginal hysterectomy five years ago. She has continued to have some difficulty with loss || of urine upon coughing or sneezing. I had given her some samples of Ditropan last year but || *SShZ *^ *t0 *^ *theSe’ *ShS *feelS *that *her *wei^ contributes a ^reatleal *Z *££ problems *with *mcontmence She has had some continuing problems with depressive *sympW *S^e cries very easily and it is getting a little bit worse. She also feels very *withdrawn *She tells roe that her sister in Florida had a similar history and was on *Paxil and did.

Original text:

[Typed page with notes document]

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Page 52: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

OCR results – An example extracted document – 3

Extracted text:

*2j*»rlfar Cardiology || *^^m Chart: *3£4U3& *Dr *-^ || *0 _. *, Medications: *Adenosinc *Dose: || Dose: *jjj&f»- *f-^- *\ *Dobutaimne

Original text:

[Pictures and Graphs document]

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Page 53: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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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Page 54: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

OCR results – Context metrics Text location awareness – PARTLY SATISFIED – columns only

• Does the data extraction technology output provide an indication of where the text is on the page?

Table search – VERY LIMITED – recognised individual columns, not tables• Does the data extraction technology recognise tables and support searching within them?

Diagram detection – VERY LIMITED – recognised as “not text”• Does the data extraction technology recognise diagrams and support searching within them?

Graph detection – VERY LIMITED – as for diagram detection• Does the data extraction technology recognise graphs (charts) and support searching within

them?

Dealing with uncertainty – SATISFIED – all engines highlighted uncertain text • Does the data extraction technology recognise entities on the page that it cannot translate and

highlight this?

Text emphasis – PARTLY SATISFIED – could, but not always correct• Does the data extraction technology recognise when the author of the document has selected a

particular item of text for special emphasis?

Multiple selection lists – VERY LIMITED – words and columns, but no “meta” info• Does the data extraction technology recognise multiple selection lists and can it identify the

item(s) selected?

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Page 55: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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. ”

Page 55

Page 56: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

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!!!

Page 56

Page 57: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Conclusion

What is needed is a framework for evaluating “reasonableness”

Based on quantifiable metrics

Reliable, repeatable, consistent, robust

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Page 58: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

A framework for assessing acceptability – 1

Stage 1 – Identify each target user group/persona• e.g. blind users, >65s, etc.

Stage 2 – Identify each component step in the interaction per group• e.g. press Enter, activate OK button, move cursor to icon, etc.

Stage 3 – Compare number of steps per group• e.g. 10 for able-bodied, 30 for blind using screen reader

DECISION GATEWAY 1

Are the numbers of steps roughly equal?

If not – differences need to be justified or remedied

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Page 59: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

A framework for assessing acceptability – 2

Stage 4 – Perform user studies with baseline user group• Calculate times, error rates, etc.

Stage 5 – Perform user studies with target user groups• Calculate times, error rates, etc.

DECISION GATEWAY 2

Could all of the users complete the task?

If not – causes of difficulties need to be removed or remedied

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Page 60: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

A framework for assessing acceptability – 3

Stage 6 – Compare error rates for each group• e.g. 2 per trial able-bodied, 5 per trial blind using screen-reader

DECISION GATEWAY 3

Are the error rates the same or similar across user groups?

If not – significant differences have to be justified or remedied

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Page 61: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

A framework for assessing acceptability – 4

Stage 7 – Compare times to complete tasks for each group + modifiers• e.g. number of component steps per group +• proportion of component steps affected by group disabilities +• relative importance of each step (3 = critical, 1 = peripheral) +• relative severity of the level of disability +• additional latencies from AT used

DECISION GATEWAY 4

Are the modified times the same or similar across user groups?

If not – significant differences have to be justified or remedied

Page 61

Page 62: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Coming to a lecture room near you…

User trials• How to plan the trials• How to select users• How to conduct the sessions• How to analyse the data gathered• How to make design recommendations

Designing and evaluating for unusual circumstances• Airports• Mobile phones

Making the business case for usability• How to calculate the “bottom line” impact

Project• Finishing your design and then testing with “real” people!

Page 62

Page 63: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Exercise

Page 63

Page 64: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

Exercise – part 1

Perform an exclusion analysis on your web-site • (As you did on Wednesday)

Prepare a summary of your calculation• Assumptions• Levels of capability required• Exclusion (total and %age) for 16+ and 75+

Make any changes necessary to your site• + any outstanding ones from last couple of weeks

Page 64

Page 65: © Simeon Keates 2009 Usability with Project Lecture 10 – 09/10/09 Dr. Simeon Keates

© Simeon Keates 2009

And finally…

Turn to the back page of today’s handout…

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