DUET: Distinct but United Event-based Timelines

Through innovations in sensors and storage, event-based data collection has increased significantly in recent years. Personal security cameras allow users to collect event data in their homes, Google Maps allows users to view places they have been throughout the day, and web browsers collect a history of the sites users visit. Despite the innovations in event-based data collection, the Graphical User Interfaces (GUIs) designed for these systems have not changed for years. Many applications stick to a linear timeline to display the events, leading to large downtime gaps when sparse events occur throughout the day. However, linear timelines create a natural sense of temporal perception since users can easily tell what time of day certain events occur. Our project seeks to find a balance between the natural temporal perception that linear timelines offer and improving the usability of visualizing event-based data using timelines. Through our design, users will be able to leverage the simple temporal perception that a linear timeline provides and avoid unnecessary searching to locate specific events. By seamlessly integrating a linear timeline with density visualizations and a timeline of events, we aim to allow users to search and view events easily. To evaluate our interface, we conducted two usability studies, first with specialists who view security camera information often and then with all individuals. Our findings inform the design of future event-based timeline visualizations.