Card sorting aims to understand how users intuitively categorize content on a website. A helpful tool for improving information architecture, this technique can be done on-site with participants placing content cards into categories and naming them accordingly, followed by questions from a moderator for further clarification and insights. It can also be done as an online unmoderated effort, which decreases cost and increases sample size. Card sorting is usually done early in the navigational design process and later validated with tree testing.