This article explores how people perceive interactive activities in order to inform navigation history design on mobile devices. Following event segmentation method, 12 participants were asked to break 6 episodes of mobile interaction into segments, organize the segments, and identify those deemed representative. Three findings emerged. First, when making sense of mobile interaction, users concentrate on the content objects on which actions are performed. This indicates the value of content-centric designs in navigation history and other mobile user interface designs. The content objects are data objects and their collections meaningful to the person dealing with it, for example, photos, messages, or albums. Second, users tend to employ two-level hierarchies in grouping segments, and use the similarity in content objects and applications as a reference. They deem the segments as representative where objects are created or changed, or where sharing or querying acts take place. These findings indicate how a navigation history design should organize and prioritize mobile interaction events. Finally, event perception shows relatively low interparticipant consensus, which indicates that navigation history designs have to accommodate large individual differences.Imagine seeing somebody using a mobile web browser intensively to find information about, say, flight departures from the Boston airport. The episode would probably take somewhere between 10 s and 10 min to complete, during which you would see the user clicking links, typing information into search fields, clicking buttons, scrolling up and down, and so on. Now, another observer could perceive exactly the same events in some other way, perhaps in terms of navigation, querying, browsing, or searching for information.Understanding how people perceive interactive activities could be useful input for navigation history design. A design of navigation history typically collects, organizes, and presents past views or a summary of past views for users to