Core Consulting Curriculum Development Status Update

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Usability with ProjectLecture 4 18/09/09
Susanne Frennert
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Use of the heuristics

• Use is two-stage
• 1 To indicate the types of areas to consider
  when looking for problems
• 2 To classify the problems when you find them
• Remember look for problems, then classify
• Not the other way around!

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Your presentations

• Over to you

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Approaches to design
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Approaches to design (source Keates and Clarkson
Countering design exclusion)
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A stage-based model of the design process
(source BS7000 1 Guide to managing innovation)
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An alternative stage-based approach

• Clarification of the task
• Take vague idea/market need and identify true
  requirements and constraints
• OUTPUT Design specification
• Conceptual design
• Generate concepts with the potential to meet the
  functional and phsyical requirements in the
  design specification
• OUTPUT Concept
• Embodiment design
• Lay foundation of detail design through
  structured development of concept
• OUTPUT e.g. detailed layout drawing
• Detail design
• Specify precise shape, dimensions, tolerances,
  etc.
• OUTPUT e.g. blueprints

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Better models of design

• Stage-based models typically focus on modelling
  process of design
• More emphasis needed on meeting the products
  acceptability targets
• Need to add 2 important questions
• Verification Are we building the product
  correctly?
• Validation Are we building the correct product?

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The waterfall model
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The waterfall model

• Assumes that
• All the requirements are identified by the start
• All the system is analysed
• All the system is designed
• All the system is written
• All the system is tested
• All the systems is handed over to the client
• There is only one run through the life cycle

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Problems with waterfall model

• Assumes logical development of ideas. It assumes
  that one stage finished before the next one
  starts.
• What if the stakeholders thinks of important
  requirements later in the project?
• What if the stakeholders requirements change
  during the project?
• Users are not involved in the validation until
  acceptance testing (in the end)
• What if the system handed over to the client does
  the wrong thing?
• The idea of iteration was not embedded in the
  original waterfall model

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A systems approach to designing

• Evaluation of acceptability (verification and
  validation) is crucial
• Provides evidence of performance (whether good
  or not)
• Additionally, evaluation of product must be done
  in context of its use
• For genuine usability (and inclusivity) where
  the product is part of a system, the entire
  system should be evaluated
• Where the product is a service, the entire
  service delivery chain should be evaluated

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An example of a systems approach The V-model
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Iterative models of design

• Most classical models still represent design as
  largely linear
• In reality, most design is iterative (design,
  evaluate, design, evaluate)
• Newer models reflect this

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Shigley and Mischke Optimisation and iteration
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Other approaches to design

• All models so far are engineering models of
  design
• Focus on practical acceptability
• i.e. utility and usability
• Alternative approach from product design
• More focus on social acceptability
• i.e. aesthetics, desirability and branding

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A practitioners model of design The IDEO
approach
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Another view of design

• A product-centred approach
• A user-centred approach

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The user-loop A model of user involvement in
design
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The three principles of user centred design are

• Early focus on users and tasks
• Understanding who the users will be, by directly
  studying their characteristics
• Empirical measurement
• Users reactions and performance to scenarios,
  simulations, and prototype are observed, recorded
  and analysed
• Iterative design
• When problems are found in user testing, they are
  fixed and more tests and observations are carried
  out

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Four basic activities in the design process

• Identify needs and establish requirements
• Design potential solutions ((re)-design)
• Choose between alternatives (evaluate)
• Build the artefact

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Heuristics as a design approach
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Five attributes of Usability (Nielsen, 1994)

• Learnability system is easy to learn so users
  can get started quickly
• Efficiency system should be easy to use,
  resulting in high productivity
• Memorability system should be easy to remember
• Errors system should have low error rate and
  allow error recovery
• Satisfaction system should be pleasant to use

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Setting the scene

• Rehabilitation Robotics in Europe c.1997
• EU funded many projects under TIDE initiative
• LOTS of money!!!
• Projects generally major disasters
• Lets see why

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An example The EPI-RAID robot

• The RAID workstation allows users to
• move books from a book shelf to a reader board
  and back again
• turn single and multiple pages in books
• discard documents
• staple documents
• insert floppy disks
• insert CD-ROMs
• drink with a straw

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EPI-RAID failed because

• No in-built market to sell to
• Had to sell on its own merits
• Too expensive
• (5000000DKK)
• Overtaken by new technology
• Internet
• Not enough consideration of what it was to be
  used for
• Too much focus on the technology

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Question

• Can we use Nielsens heuristic in the design
  process?
• i.e. not just for post-hoc testing

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Exercise
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Exercise

• Work as a group
• Write a script (task analysis) for how you
  envisage each of your personas would use your
  site
• Try to follow that script using your site
• Log any problems you encounter
• Then try another groups site (more if you have
  time)
• Make any changes to your site based on your
  evaluations

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Task scenarios

• Purpose
• To provide examples of usage as an input to
  design, and to provide a basis for subsequent
  usability testing. Scenarios specify how users
  carry out their tasks in a specified context. To
  maintain design flexibility, they should not
  specify what product features are used
• Try to generate scenarios to cover a wide range
  of situations, not just the most common ones or
  those of most interest to you
• Try to include problem situations that will test
  the system concept, not just straightforward
  scenarios
• Work through the scenarios fully and judge the
  system on that basis rather than trying to change
  the system half way through