Topic: difference between usability and userinterface tes

These both fall under two different types of testing: functional and non-functional testing.

GUI testing is functional testing - ensuring that all interactions, navigation, links,

pop-ups, content, etc all work as required. Every aspect of the interface must be tested and

this can usually be done by developing tests based on your product's functional requirements

(if these are documented).

Usability testing is non-functional testing, which involves testing against non-functional

requirements such as standards or development guidelines. These non-functional requirements

place certain design contraints on the development activity, but don't actually explicitly

state how the product should function.

Usability requirements are typically based around some popular guidelines, such as Nielsen's

"Ten Heuristics" or Schneiderman's "Eight Golden Rules". These will typically be things like

design consistency, ease of use, informative feedback, easy reversal of actions and

learnability - all things that you should test by observing actual user behaviour in the

field, not by a tester from your company.

Searching on Google for terms like software user trials, software focus groups, usability

testing, user testing should all yield information on standard practices for this type of

testing.