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UKOLN is supported by:

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Help users recognise, diagnose & recover from errors: Are error messages useful? ... Do not be surprised if you get some funny looks. ... – PowerPoint PPT presentation

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Title: UKOLN is supported by:


1
Usability testing for the WWW Emma Tonkin UKOLN
UKOLN is supported by
www.bath.ac.uk
2
Introduction
  • UKOLN, the University of Bath
  • Why this session?

3
Why do projects fail?
  • Project Impaired Factors of the Responses
  • 1. Incomplete Requirements 13.1
  • 2. Lack of User Involvement 12.4
  • 3. Lack of Resources 10.6
  • 4. Unrealistic Expectations 9.9
  • 5. Lack of Executive Support 9.3
  • 6. Changing Requirements Specifications 8.7
  • 7. Lack of Planning 8.1
  • 8. Didn't Need It Any Longer 7.5
  • 9. Lack of IT Management 6.2
  • 10. Technology Illiteracy 4.3
  • 11. Other 9.9

4
Introducing usability
  • Definition the measure of a products potential
    to accomplish the goals of a user
  • How easy a user interface is to understand and
    use
  • Ability of a system to be used easily?
    Efficiently? Quickly?
  • The people who use the project can accomplish
    their tasks quickly and easily

5
Assumptions
  • There are several dimensions to usability
  • Focus on users
  • People use products to be productive
  • Users are busy people trying to accomplish tasks
    quickly
  • Users decide when a product is easy to use
  • (Adapted from Redish Dumas, A Practical Guide
    to User Testing)?

6
However
  • Are users always busy? Does this imply that
    usability is only present in the workplace?!
  • Effectiveness vs. efficiency vs. satisfaction
  • Do users know when a product is ready?
  • Do all users agree about usability?
  • Is usability actually measurable?
  • Is there one statistic that usability?

7
Elements of usability
  • Nielsen refers to five elements or components of
    usability
  • Learnability
  • Efficiency
  • Memorability
  • Errors
  • Satisfaction
  • Usability Engineering, 1993, p.26
  • These may not be of equal importance in all cases.

8
In other words
  • Usability depends on context
  • What does the user want to do?
  • Who is the user?
  • Related to
  • Internationalisation cultural, social issues
  • Task analysis working out what the user wants to
    do (what the goal is) and how he/she would expect
    to accomplish it

9
Science vs craft
  • Formal approaches
  • Research-driven
  • hard science
  • Laboratory-based
  • Informal approaches
  • Naturalistic, qualitative observations
  • Informal setting

10
User model vs user testing
  • Either we apply our understanding of the way
    users act, and test the interface that way
  • Or we simply observe users...

11
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12
A note about rule-based testing/validation
  • Should be vs is model vs reality
  • Great handwriting does not guarantee a
    compellingly readable result

13
Scenario-based user testing
  • Based around tasks
  • Simple scenarios (hypothetical
    stories/abstract-level test cases)
  • For a company web page, locating and using
    contact details
  • Registration and login to a wiki
  • Process provide a task and ask the user to
    complete it
  • It is important to test the right tasks!

14
Cognitive walkthrough
  • Works something like this

Task Climb mountain and find the highest peak
15
Required for CW
  • A description of the interface
  • A task scenario
  • Assumptions What knowledge does the user already
    have?
  • Functionality What actions will accomplish the
    task with this interface?

16
Method
  • Look at each step that is required to accomplish
    the task
  • Will the user try this step?
  • Will the user notice that this action (control,
    button, switch) is available?
  • Will the user associate this action with the
    effect that they are hoping for?
  • If this action is performed, does it appear that
    progress is being made?
  • Can you 'tell a success story' for each step? If
    not, there is a usability problem.

17
Recording your test
  • Create a diary format
  • Trying to achieve whatever
  • Looking for something that does whatever
  • Found a button marked foo
  • But clicking on foo took me to unrelated-looking
    screen blah
  • Like the mountain-climbing line, you can go back
    and try another trajectory document this in a
    similar way.

18
Developing appropriate task scenarios
  • Probably the hardest thing about any usability
    testing
  • On the one hand, you are not required to support
    very improbable scenarios.
  • On the other hand, developing and supporting
    probable scenarios is key to a user-centred
    development process.

19
Trying out a CW
  • Who's got a mobile phone?
  • In groups
  • Work out a couple of tasks.
  • Working from the perspective of a user with an
    appropriate level of knowledge (you will have to
    define what that means!), try the tasks. Document
    the result.

20
User testing (with real users!)?
  • The popular example is heuristic evaluation.
  • Heuristics are rules of thumb.
  • Heuristic evaluation requires about six people
    and a large amount of coffee.
  • Provide them with a list of the ten (or twelve,
    or...) heuristics, and ask them to examine each
    page ('screen') for problems, according to the
    heuristics.

21
Ten heuristics
  • Visibility of system status Does the system
    give timely appropriate feedback?
  • Match between system and the real world Is it
    speaking the users language?
  • User control and freedom How hard is it to undo
    unwanted actions?
  • Consistency and standards Does it follow
    conventions and expectations?
  • Error prevention Are potential errors
    recognised before becoming a problem?
  • Recognition rather than recall Does the system
    rely on the users memory?
  • Aesthetic minimalist design Are dialogs
    cluttered with information?
  • Help users recognise, diagnose recover from
    errors Are error messages useful?
  • Help and documentation Is there online help? Is
    it useful?

22
Evaluating the results
  • Again, a diary form can be helpful 'Screen 1
    violates heuristic 10 because...'
  • Merge these notes.
  • List by frequency order to see most obvious bugs
  • List by heuristic to see severity for your
    purposes

23
Applying the results
Low-hanging fruit?
Bug fixes
Strange interaction flow
Misnamed element
Confusing colours
Feature requests
It would be much easier if this textbox
autocompletedthe system remembered my email
preferences
Major objections
I dont like type of applicationI prefer
totally different type of application
(Oh)?
24
Testing layouts via greeked text
  • Wasn't going to talk about this, but it's turned
    out to be useful
  • Early stage of web site design often involves
    developing layouts/templates
  • Because no real content exists yet, these may be
    hard to test using the above methods
  • However, a layout should communicate something
    about page function. Does it?

25
Preparing a template
  • Get greeked text from the Lorem Ipsum generator
  • http//lorem-ipsum.perbang.dk/
  • Place it into template. Do not leave a single
    readable word!
  • Make yourself a list of elements that should be
    visible on the page
  • Find/bribe about six test subjects

26
Example list
  • Main page content
  • Page title
  • Person responsible for page
  • Navigation elements
  • Last updated date
  • Logo
  • How to get back to the front page?
  • News items

27
Testing process
  • One user at a time
  • On each layout 'greeked', ask the user to
    identify each element or group of elements. If
    they can't find it, invite them to mark where
    they think it ought to be.
  • Asking the user to 'think aloud' can be helpful
  • Also, ask the user to give a mark (out of ten, or
    from -3 to 3, or whatever...) on 'subjective
    appeal'
  • Note Randomising order reduces systematic error

28
Coming up with a preamble
  • This is a strange thing to ask someone to do. Do
    not be surprised if you get some funny looks.
  • Come up with a short, reassuring introduction to
    the test. Useful items to include
  • Introducing the software (purpose, not detail)?
  • Your participation will help us...
  • Remember, we are testing the software, not your
    performance...
  • Please think out loud...
  • This style of test helps us to...

29
Examining the results
  • Build a table
  • As the layout is improved, the number of
    misidentified elements should reduce

30
Creating scenarios
  • Must be
  • Motivating
  • Credible
  • Complex
  • Provide easy-to-evaluate results
  • An Introduction to Scenario Testing, Cem Kaner,
    Florida Tech, June 2003
  • Can be gleaned from documented requirements?

31
The test process
  • A facilitator with detailed knowledge about the
    site/software is chosen to oversee the test
  • They must take care not to influence the users
    behaviour!
  • The tester (user) is briefed about the
    site/software
  • They then go through each scenario
  • Think-aloud method describing and explaining
    actions
  • Talk-aloud method describing without
    explanation (considered more accurate)?
  • The facilitator keeps notes and prompts the user
    where necessary
  • Alternatively/additionally, the session can be
    videoed
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