Title: UKOLN is supported by:
1Usability testing for the WWW Emma Tonkin UKOLN
UKOLN is supported by
www.bath.ac.uk
2Introduction
- UKOLN, the University of Bath
- Why this session?
3Why 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
4Introducing 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
5Assumptions
- 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)?
6However
- 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?
7Elements 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.
8In 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
9Science vs craft
- Formal approaches
- Research-driven
- hard science
- Laboratory-based
- Informal approaches
- Naturalistic, qualitative observations
- Informal setting
10User 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(No Transcript)
12A note about rule-based testing/validation
- Should be vs is model vs reality
- Great handwriting does not guarantee a
compellingly readable result
13Scenario-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!
14Cognitive walkthrough
- Works something like this
Task Climb mountain and find the highest peak
15Required 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?
16Method
- 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.
17Recording 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.
18Developing 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.
19Trying 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.
20User 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.
21Ten 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?
22Evaluating 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
23Applying 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)?
24Testing 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?
25Preparing 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
26Example 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
27Testing 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
28Coming 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...
29Examining the results
- Build a table
- As the layout is improved, the number of
misidentified elements should reduce
30Creating 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?
31The 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