A computing device is described that can receive contextual information related to a user associated with the computing device. The contextual information may relate to at least one of a physiological condition of the user at a current time or a type of activity associated with the user at the current time. The computing device can select, based at least in part on the contextual information, a type of alert to output as an indication of notification data. The type of alert may include at least one of an electric stimulus type alert, a shape-memory alloy type alert, and a vibration type alert. Responsive to selecting the type of alert, the computing device can output an alert based on the notification data, the alert being of the selected type of alert.