A system for delivering learning programmes comprising optical sensors for capturing a subject's facial expression, eye movements, point-of-gaze, and head pose during a learning session； a data repository comprising task data entities； a module for estimating the subject's affective and cognitive states using the captured sensory data； and a module for selecting a task data entity for presentment to the subject after each completion of a task data entity based on a probability of the subject's understanding of the associated knowledge； wherein the probability of the subject's understanding is computed using the subject's estimated affective cognitive states.
