A method may include receiving implicitly collected computer interaction data of a user from a computing device; accessing a data store of previously collected computer interaction data, the previously collected computer interaction data correlated with sleep patterns of users; comparing the users implicitly collected computer interaction data to the previously collected computer interaction data; and inferring the user's sleep pattern based on the comparing. The method may provide an indication of real-world cognitive performance that varies throughout the day, and which is influenced by both circadian rhythms, chronotype (morning/evening preference), and prior sleep duration and timing.