User Interface Design and Ergonomics - National Open University of ...

The users of a system must be identified. In the case that the population of users is large,
a reasonable and representative sample of users should be identified.
b. Learning About Users’ Tasks
The interface designers should interact with the users in order study their tasks. The
major interests here are:-
What kind of tasks are they performing
Identify what the users want to do (minor and major tasks) and how they want to
do it
How do users want the work to be done?
Identify how users’ tasks can be performed better
State the examples of concrete tasks perform by users
Who will do what
They extent of work to be done
The level of interaction required by the tasks
c. Come Up With A Representative Task Description
After establishing a good understanding of the users and their tasks, a more traditional
design process might abstract away from these facts and produce a general specification
of the system and its user interface. The task-centered design process takes a more
concrete approach. The designer should identify several representative tasks that the
system will be used to accomplish. These should be tasks that users have actually
described to the designers. The tasks can initially be referenced in a few words, but
because they are real tasks, they can later be expanded to any level of detail needed to
answer design questions or analyze a proposed interface. Here are a few examples:
for a word processor: "transcribe a memo and send it to a mailing list"
for a spreadsheet: "produce a salary budget for next year"
for a communications program: "login to the office via modem"
for an industrial control system: "hand over control to next shift"
Again, these should be real tasks that users have faced, and the design team should
collect the materials needed to do them: a copy of the tape on which the memo is
dictated, a list of salaries for the current year and factors to be considered in their
revision, etc.
The tasks selected should provide reasonably complete coverage of the functionality of
the system, and the designer may want to make a checklist of functions and compare
those to the tasks to ensure that coverage has been achieved. There should also be a
mixture of simple and more complex tasks. Simple tasks, such as "check the spelling of
'occasional'," will be useful for early design considerations, but many interface problems
will only be revealed through complex tasks that represent extended real- world
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