Usability Testing is a Black Box Testing Technique. Usability testing is done with users point of view. It is a technique implemented in user-centred interaction design to evaluate a product or service by testing it with representative users. On the Web page the usability is a most important and required condition for survival. If the website is difficult to use then peoples will not stay on the page. If the page content or details are hard to read or understand then also peoples will leave the page. So Usability testing plays an important role which assesses how easy user interfaces is to use
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