Transcript Why Conduct a Task Analysis?  Uncovered Information may lead to abandoning a bad idea – The world is ready for video telephones – Users.

Why Conduct a Task Analysis?

Uncovered Information may lead to
abandoning a bad idea
– The world is ready for video telephones
– Users want recipe management programs
Copyright 1999 all rights reserved
Why Conduct a Task Analysis?
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Uncovered
information drives
the design
– without it, we are
designing in the dark
– keeps us from
building a useless
program
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Information Captured Through
Task Analysis

User’s goals in performing a
task
– What are they trying to
accomplish?
– What subgoals do they generate
as a result of their primary goal?
– What external representations in
the environment help the user to
keep track of their goal?
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Information Captured Through
Task Analysis

Work flow patterns
– frequency of
different tasks
performed - how
often is A done, B
done, etc.
– grouping of work
tasks - what is done
with what
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Information Captured Through
Task Analysis

Work flow patterns
– order of work tasks what is done first,
why?
– communication
patterns - who talks
to whom about what
– exceptions - when is
A not done, why?
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Information Captured Through
Task Analysis

Users’ conceptual model
– What is the external
representation that is used
to do the task worksheets, patient charts
– What organization or
model do users keep in
their head as they are
doing the task?
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Information Captured Through
Task Analysis

User Characteristics
– Task experience and
knowledge of the
domain, e.g.,
radiologists, bakers,
sailors
– System experience,
e.g., special keys,
conventions, syntax,
commands, etc. for
this system
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Information Captured Through
Task Analysis

User Characteristics
– Application
experience, e.g.,
other word
processors
– Computer literacy,
e.g., used word
processors, but first
time using
spreadsheet
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Task Analysis Methods:
Data Gathering
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Lots of task analysis methods
None completely satisfactory
Typical Methods
–
–
–
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Questionnaires and interviews
Observational studies
Examination of competing, or similar products
Experimental data collection
Unstructured user input
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Questionnaires and Interviews
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Talk to a number of representative users
Talk to key users
Plan interview
– Preset questions to address issues identified in
advance
– Always provide flexibility for additional info
– Provide mechanism for recording data easily
– Design to have quantitative results
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Questionnaires and Interviews
(continued)

Keep the number of questions low
– Only questions with answers that you can’t get
other ways
– Only questions that will have a direct impact on
functional requirements
– Avoid asking for everything
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Questionnaires and Interviews
(continued)

Ask clear questions
– Can the user understand your question?

Ask questions that users can answer validly
and reliably
– Does the user store information in this way?
– Does the user remember such information?
– Will the user be inclined to answer your question
truthfully?
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Observational Studies

Describe and
analyze current
practice

Note organization of
functionality
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Note expectations &
concerns of users
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Observational Studies
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Collect quantitative
data
– How many?
– How often?
– How long?
– What order?
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Study Similar or Competing
Products
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Incorporate features that users like
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Be creative in thinking up possible
similar products
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Run usability studies on competitors'
products
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Unsolicited Comments from
Users
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Effective when updating an existing product
Keep track of frequency of comments
Information that is readily available
– Internet comments
– Suggestions fostered by offering
incentives
– User hotline conversations
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Unsolicited Comments from
Users
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Don’t believe everything users say
– Confirm usefulness of suggestions
with other techniques
– Users have lots of opinions but often do
not mentally have access to their
performance record
• users often retype an entire paragraph when it
would have been faster to edit it
• retyping is prone to new errors
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