Evaluating User-Interface Design Without Users
There are good reasons for performing evaluations without users
(in addition to testing with users):
- Users have only limited time for taking part in the design and
evaluation. Therefore, the user-interface should be free of (trivial) problems
which can be easily foreseen and avoided.
- Evaluation with only a few users may not reveal all problems a large
number of final end-users will experience, because not all possibilities
of the application and user-interface will be tried.
- While the user-interface is being developed the test-users are still
learning the interface. They may not encounter the problems experienced
users will encounter later.
There are three popular evaluation techniques which are performed
without involving test-users:
- cognitive walkthrough:
this technique is especially useful for task-centered design.
- action analysis:
this technique is used to estimate the time an expert user will need to
perform a task using the interface.
- heuristic evaluation:
using a checklist one may catch a wide variety of problems, but this technique
requires evaluators with knowledge of usability problems.