There are some good reasons why you might use this technique:
It can be a quick and inexpensive way to generate feedback for designers
It can be used pretty early in the design process
It can give a more comprehensive assessment of the system than usability testing
Assigning the correct heuristic can suggest a good place to start for corrective measures
You can use it together with other usability methods
But there are also some fundamental problems with the technique, so it is critical that you understand its limitations and dangers too:
For it to be done well, the evaluators should ideally be double-experts; usability experts as well as experts in the subject domain of the project (i.e. finance, education, insurance, etc.)
You need to use more than one evaluator—this is often forgotten. A single expert working in isolation may only pick up 20% of the usability issues. Even ten experts may only surface 85%. A good compromise between effectiveness and practicality is to use between 3-5 evaluators, which gives you about a 60% hit rate.
Finding people suitable as evaluators can be difficult, and nowadays it may turn out to be more expensive than running a proper usability test with 5 participants.
Using heuristics to identify usability issues is a relatively black-and-white approach. It will identify more minor issues than usability testing, but it will also have plenty of ‘false positive’ issues that aren’t really problems at all.
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