• text comments – Comments about a single item are collected and presented to the
users as a means of facilitating the decision-making process, such as in [72]. For
instance, customer’s feedback at Amazon.com or eBay.com might help users in
deciding whether an item has been appreciated by the community. Textual com-
ments are helpful, but they can overload the active user because she must read
and interpret each comment to decide if it is positive or negative, and to what de-
gree. The literature proposes advanced techniques from the affective computing
research area [71] to make content-based recommenders able to automatically
perform this kind of analysis.