Some humans just know when and how to offer a word of emotional support. Now computers are learning too, with the creation of a new algorithm that aims to deliver the right words at the right time. "There's a lot of need for emotional support at the moment," says Judith Masthoff at the University of Aberdeen, UK, who is designing the system. "We have increased rates of mental health issues, and this has led to increased rates of informal care." Trained professionals are only available for the most extreme cases, so Masthoff suggests that people could get instant support from apps instead.

Most of the existing personalization systems such as content recommenders or targeted ads focus on individual users and ignore the social situation in which the services are consumed. However, many human activities are social and involve several in-dividuals whose tastes and expectations must be taken into account by the system. When a group profile is not available, different profile aggrega-tion strategies can be applied to recommend ade-quate items to a group of users based on their indi-vidual profiles. We consider an approach intended to determine the factors that influence the choice of an aggregation strategy. We present evaluations made on a large-scale dataset of TV viewings, where real group interests are compared to the pre-dictions obtained by combining individual user profiles according to different strategies.