Validation phase - System Testing - Usability Testing

Usability is the degree to which a user can easily learn and use a product to achieve a goal. It is the system testing that attempts to find any human factor problems. It is testing the software from a user's point of view. Essentially, it means testing software to prove or ensure that it is user friendly. It includes ergonomic considerations, screen design, standardization etc.

The idea behind usability testing is to have actual users perform the tasks for which the product was designed. If they can not do the tasks or if they have difficulty performing the tasks, the user interface is not adequate and needs redesigning. Usability testing is just one of the many techniques that serve as a basis for evaluating the user interface in a user-centered approach. Other techniques for evaluating a UI include inspection methods such as heuristic evaluations, expert reviews, card sorting, matching test or icon intuitiveness evaluation, cognitive walk-through. Confusion regarding usage of the term can be avoided if we use usability evaluation for the generic term and reserve usability testing for the specific evaluation method based on user performance.

It often involves building prototypes of parts of the user interface, having representative users perform representative tasks and seeing if the appropriate users can perform the tasks. In other techniques such as inspection methods, it is not performance, but someone's opinion of how users might perform that is offered as evidence that the UI is acceptable or not. This distinction between performance and opinion about performance is crucial. Opinions are subjective. Whether a sample of users can accomplish what they want or nit is objective. Under many circumstances it is more useful to find out if users can do what they want to do rather than asking someone.

The end goals of usability testing is to get:
- a better quality software.
- a software that is easier to use.
- a software that is more readily accepted by users.
- a method that shortens the learning curve for new users.