Asking Users and Experts

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Asking Users and Experts

• Li Zhang (Jacey)
• Yuewei Zhou (Joanna)

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Asking Experts

• Why Experts?
• Users are not easily accessible
• Too expensive
• Takes too long
• Then
• Ask experts to provide feedback.

3
Experts Inspection

• How ?
• Experts inspect the human-computer interface
  and predict problems users would have when
  interacting with it.

• Advantages
• Relatively inexpensive
• Easy to learn
• Effective
• Can be used at any stage of a design project

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Inspection Techniques

• Heuristic evaluations
• Walkthroughs

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Heuristic Evaluation

• Informal usability inspection technique
• Experts review guided by a set of heuristics
• ( usability principles )

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Core Heuristic

• Visibility of system status
• Match between system and the real world
• User control and freedom
• Consistency and standards
• Help users recognize, and recover from errors
• Error prevention
• Recognition rather than recall
• Flexibility and efficiency of use
• Aesthetic and minimalist design
• Help and documentation

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Problems?
Go Specific!
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Example Commercial Websites
HOMERUN ! (Nielsen, 1999)

• High-quality content
• Often updated
• Minimal download time
• Easy of use
• Relevant to users needs
• Unique to the online medium
• Netcentric corporate culture

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Conclusion

• Which heuristics are the best, and How many are
  needed are debatable and depend on product.

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How to do Heuristic Evaluation

• Stage 1 Briefing Session
• Experts are told what to do.
• Stage 2 Evaluation Period
• Two passes 1st gain overall feeling of the
  system. 2nd focus on specific interface
  elements.
• Stage 3 Debriefing Session
• Experts come together , discuss their findings
  suggest solutions.

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Dilemma

• About 33 reported problems are real usability
  problems.
• Sometimes heuristic evaluation misses severe
  problems. Heuristic evaluation misses about 21
  of users problems.
• 43 are not problems at all.

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Solutions

• Use complementary user testing techniques along
  with heuristic evaluation.
• Get really good or experienced evaluators
• Have several evaluators to avoid one persons
  bias or poor performance.

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Efficiency

• Five evaluators can identify around 75 of the
  total usability problems

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MedlinePlus example

• Medical information website
• Provides health information for patients,
  doctors and researches.

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Heuristics and Evaluation

• Internal Consistency
• Simple Dialog
• Shortcuts
• Minimizing Memory Load
• Preventing Errors
• Feedback
• Internal locus of control

7 heuristics were used 3 expert evaluators
did independent evaluation
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Improvement Suggestions

• Layout Uncomplicated Vertical Design well
  suited for printing conservative using of
  graphics
• Internal Consistency Formatting of pages and
  logo is consistent across the website.
• Arrangement of health topics Problems should be
  arranged alphabetically as well as in categories.
• Depth of navigation menu increase the fan-out in
  navigation menu in the left margin.

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General Web Design
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Guidelines for Web Design
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Heuristics For more.

• For online communities
• Sociability
• Usability
• For other devices
• handheld, computerized toy
• More

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Walkthroughs

• Cognitive Walkthroughs
• Pluralistic Walkthroughs

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Cognitive Walkthroughs

• Simulating users problem-solving process at each
  step in the human-computer dialog
• Checking to see if the users goals and memory
  for actions can be assumed to lead to the next
  correct action
• They focus on evaluating designs for ease of
  learning

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Cognitive WalkthroughsSteps

• Identify characteristics of typical users
  Develop sample tasks Produce the interfaces
  prototype, or a description of it Generate a
  clear sequence of the actions needed for the
  users to complete the task
• A designer and one or more experts begin the
  analysis
• Evaluators walk through the sequences for each
  task, and try to answer the following questions
• 4. Record critical information, including
• Assumptions about what would cause problems and
  why
• Notes about side issues and design changes
• A summary of the results
• 5. Revise the design according to the results.

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Finding a book at Amazon.com

• Task find a at
• Typical user students who use web regularly
• Step 1 selecting the correct category of goods
  on the homepage
• Step 2 complete the request form
• Questions
• Will user know what to do?
• Will users see how to do?
• Will User understand from feedback whether the
  action is correct or not?

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Cognitive walkthroughs vs Heuristic Evaluation

• It provides much more detailed information
• It takes longer than heuristic evaluation for the
  same part, because it examines each step of a
  task.
• Its useful to examine small part of a system
  whereas heuristic evaluation is useful for
  examining a whole system.

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Pluralistic Walkthroughs

• Users, developers and usability experts work
  together to step through a scenario, discussing
  usability issues associated with dialog elements
  involved in the scenario steps.

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Pluralistic Walkthroughs--Steps

1. Develop scenarios in the form of a series
   (usually 1 or 2) of hard-copy screens
2. representing a single path through the interface.
3. A panelist ask evaluators to write down the
   sequence of actions they take to move from one
   screen to another.
4. Discuss the actions from that round of review.
   (Users-gt Experts-gt Designers)
5. Move on to next round of screens. The process
   continues until all the scenarios have been
   evaluated.

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Benefits and Constraints of Pluralistic
Walkthroughs

• Strong focus on users task
• Involving a multidisciplinary team
• Performance data is produced and many designers
  like the apparent clarity of quantitative data.
• Limited screens each time, so it takes relatively
  long time to complete.

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• Thanks!