A form of unmoderated usability testing, card sorting allows you to quickly spot popular groupings and categories so you can better speak customers’ language—and meet their needs. It’s an especially common choice when it comes to ecommerce and web design, as your goal may be to improve site navigation, reorganize drop-down menus, or redesign the homepage.
By evaluating what test participants come up with, you can learn the reasoning behind contributors grouping something a certain way, allowing you to better design (or redesign) your product.