In general, a computing device is described that receives an indication of a particular communication from a particular sender. The computing device determines a relationship score based at least in part on a relationship context between the particular sender and a user of the computing device. The relationship score indicates a degree of strength of a relationship between the particular sender and the user of the computing device. While outputting an alert indicative of the communication, the computing device adjusts one or more characteristics of the alert based at least in part on the relationship score.