Usability Heuristics

1
Usability Heuristics

• Avoid common design pitfalls by following
  principles of good design
• Nielsen proposes 10 heuristics, others propose
  more or less.
• Inspect an interface for usability problems with
  these principles

2
Ten Usability Heuristics (from Jakob Nielsen)

• Visibility of system status
• The system should always keep users informed
  about what is going on, through appropriate
  feedback within reasonable time.
• Match between system and the real world
• The system should speak the users' language, with
  words, phrases and concepts familiar to the user,
  rather than system-oriented terms. Follow
  real-world conventions, making information appear
  in a natural and logical order.
• User control and freedom
• Users often choose system functions by mistake
  and will need a clearly marked "emergency exit"
  to leave the unwanted state without having to go
  through an extended dialogue. Support undo and
  redo.

http//www.useit.com/papers/heuristic/heuristic_
list.html
3
Nielsens Usability Heuristics (cont.)

• Consistency and standards
• Users should not have to wonder whether different
  words, situations, or actions mean the same
  thing. Follow platform conventions.
• Error prevention
• Even better than good error messages is a careful
  design which prevents a problem from occurring in
  the first place.
• Recognition rather than recall
• Make objects, actions, and options visible. The
  user should not have to remember information from
  one part of the dialogue to another. Instructions
  for use of the system should be visible or easily
  retrievable whenever appropriate.
• Flexibility and efficiency of use
• Accelerators -- unseen by the novice user -- may
  often speed up the interaction for the expert
  user such that the system can cater to both
  inexperienced and experienced users. Allow users
  to tailor frequent actions.

4
Nielsens Usability Heuristics (cont.)

• Aesthetic and minimalist design
• Dialogues should not contain information which is
  irrelevant or rarely needed. Every extra unit of
  information in a dialogue competes with the
  relevant units of information and diminishes
  their relative visibility.
• Help users recognize, diagnose, and recover from
  errors
• Error messages should be expressed in plain
  language (no codes), precisely indicate the
  problem, and constructively suggest a solution.
• Help and documentation
• Even though it is better if the system can be
  used without documentation, it may be necessary
  to provide help and documentation. Any such
  information should be easy to search, focused on
  the user's task, list concrete steps to be
  carried out, and not be too large.

5
Rating Problem Severity

• Severity is based on 3 things
• impact
• frequency
• persistence
• Ratings (modified from Nielsen)
• 0. Not a problem
• 1. Cosmetic problem should be addressed if
  schedule permits.
• 2. Grammatical, spelling, or other errors should
  be fixed as they can affect users impressions of
  the interface and its creators, but wont impact
  usability.
• 3. Minor problem should be fixed if possible as
  this will be an annoyance to users, but wont
  affect ability to achieve goals.
• 4. Major problem important to fix, as this will
  impact users ability to achieve goals.
• 5. Catastrophic problem must be fixed before
  product is released.

6
Heuristic Evaluation Methodology

• Develop a scenario of use
• identify typical user, his/her goal(s),
  expectations, background experience, knowledge,
  etc.
• define a set of objectives to be achieved
• if appropriate, sketch out users mental model of
  how the objective(s) should be achieved (based on
  previous experience, common practice, etc.)
• Access the site under consideration
• take the perspective of the user you identified
  in step 1 attempt to achieve the objectives.
• take note of the path, your impressions,
  potential problems, etc.
• Rerun the path, taking screen shots of problem
  pages
• paste pages into a Powerpoint file
• Annotate the screen shots
• circle sources of problems
• describe the problem
• assign a severity rating

7
An Example

• E-commerce web site.
• In some cases, the first impression a potential
  customer will get.
• For online retailers, the ONLY impression the
  customer will get!
• The following pages represent a portion of the
  evaluation (full evaluation can take anywhere
  from several hours to several days, depending on
  the size and complexity of the site and number of
  usability problems.)

8
3
This should let you know what might be
recalled. User must go through 3 screens to
determine if their product is recalled.
4
1
Blank space (bigger on larger screens) redesign
to resize automatically.
3
Have to scroll down to see the majority of useful
information.
9
What do we expect a visitor to want to do? Find
out about Whirlpool Corp or find out about
products these should be arranged, separated,
etc.
3
10
Too many steps to get to this point and still
several to go before I can purchase the product.
4
No way to learn anything about the retailer
just information about how to prepare for
delivery.
4
11
Your Turn

• Go to this web site and choose one link to
  follow. Perform a heuristic evaluation of the
  site as it is now.
• Spend a few minutes navigating the site. Make
  notes on your initial impressions, incidents of
  difficulty or confusion, annoying features, and
  anything that impresses you about the site. Be
  sure to note specific pages you wish to return to
  for the next step.
• Select at least 3 pages that have typical or
  particularly egregious violations of good design
  that you wish to highlight.
• Use the printscreen function to copy and paste
  each page into a Powerpoint presentation.
• Annotate the pages as shown on the previous pages
  and using the severity ratings given on slide 5.
• Send the Powerpoint evaluation to me via email.
• Perform a heuristic evaluation of your project. I
  will do the same and will send it to you by
  Friday.