Approaches to Preference Elicitation for Group Recommendation

Recommendation can be defined as the problem of selecting, among a set of items, those ones that are likely of interest to the user. In case of a group of users, recommendations should satisfy, as far as possible, the preferences of all the group members. In order to elicit the group preferences, we present two different mechanisms: the first one consists in a voting procedure whereas the second is based on a negotiation procedure. In both cases, intelligent agents act on behalf of the group members. The experimental results show the pros and cons of both approaches and highlight which of the two mechanisms returns the highest-valued recommendation for the whole group in each case. Moreover, we also study which approach is able to reflect more easily the different behaviour of each user, which is also an important aspect in group recommendation.