Definition from UX Mastery
“As the name suggests, the 5-Second Test involves showing users a single content page for a quick 5 seconds. The aim is to gather a participant’s initial impressions and assess the screen’s clarity and conciseness using simple questions like "What is the most important information on the page?" or "How would you go about achieving your goal on this screen?". The setup is similar to a standard usability test, and may sometimes be combined with one.”
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