Usability

1
Usability Design Process

• CS352
• 01/19/06

2
User-Centered Design Process

• Identify users
• Identify activities/context
• Identify needs
• Derive requirements
• Derive design alternatives
• Build prototypes
• Evaluate prototypes
• Iterate (rinse and repeat)
• Ship, validate, maintain

3
Studying Users

• Questionnaires
• Interviews
• Focus groups
• Naturalistic observation
• Ethnomethodological
• Contextual inquiry
• Participatory design
• Documentation

4
HCI Methods - Ethnography

• Writing the culture
• Ethnographer takes part in the world for extended
  periods of time, passive observer
• Observe everything taking place, activities,
  environments, interactions, practices etc
• Hidden assumption we dont always know what we
  know or do, make the implicit explicit
• Noisy, but very rich and detailed data

5
Ethnography

• Pros
• Rich descriptions, unlikely to miss details
• Exploratory
• High internal validity
• Not very disruptive to the environment
• Cons
• Dense data, a lot of detail, a lot of potential
  noise
• Not necessarily very coherent, or representative
• Time consuming and costly

6
Ethnography too Participant observation and
Contextual inquiry

• Participatory observation
• Going native
• Ethnographer part of culture, apprentice
• May be difficult to relate back
• May influence outcome
• Contextual inquiry
• Ethnographer less embedded in the culture
• Some observation followed by questions to the
  actor to clarify meaning
• Prone to rationalizations and tall tales

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Ethnographic practice

• Ethnography is an approach for studying cultural
  contexts in detail
• Artifacts
• Environment
• Actors
• Interactions
• Tasks/Activities
• Key practices
• Prolonged continuous immersion
• Speaking the users language
• Growing interest in applying to usability and IT

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Ethnographic practice

• The people who inhabit the space
• Who are they? (Students, faculty, staff, what is
  the mix?)
• What are they doing?
• How are they doing it?
• The objects in the space
• What are the functional elements?
• What are the decorational elements?
• Which do people interact with or look for?
• The building spaces, architecture, lighting etc
• What is the layout?
• What is the environment like?
• How does it influence the activities people
  engage in?
• How does the building support the objects here?
• The technology
• What technology is here (not just computer
  technology, not just electronic)
• How do people interact with it?

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Observation

• Subject knowledge/consent
• Public vs. Private spaces
• Medium
• Notebook
• Audio tape
• Video/photographs
• Transcription within 24 hours

10
Workplace artifacts

• What people use to do their work tells us a lot
  about that work
• Often, specific properties detract from the
  essential task
• But, people are good at exploiting the
  affordences of objects
• e.g. ATC stack of flight strips
• Collect samples or photos of common artifacts
• Discuss how they are used while you watch
• Artifact analysis looks only at these

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Problem with ethnography

• Data is very disorganized, typically needs
  further refinement before it can be applied
• Use cases
• Scenarios
• Task analysis
• Workflow models
• Ethnography often a good starting-off point, but
  seldom self-sufficient

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Ethics
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Learning Objectives

• Discuss key ethical concerns
• The role of the IRB
• Principles and origin of Belmont Report
• Principle of informed consent considerations
  surrounding this
• Responsibilities to participants before, during
  and after study

14
A Little History

• It is important to look at history
• We learn from our mistakes
• History can repeat itself!
• The Nuremberg Doctors Trial of 1946
• The Milgram Obedience Experiments
• Thalidomide Tragedy
• Untreated Syphilis Study
• Human Radiation Experiments

15

• http//cme.cancer.gov/clinicaltrials/learning/huma
  nparticipant-protections.asp
• http//oregonstate.edu/research/osprc/rc/humansubj
  ects.htm