Avoiding Long and Fruitless Dialogues in Critiquing

An important issue in critiquing approaches to product recommendation is how to avoid long and fruitless critiquing dialogues when none of the available products are acceptable to the user. We present a new approach called progressive critiquing in which the non-existence of a product that satisfies all the user's critiques triggers an explanation alerting the user to the possibility that none of the available products may be acceptable. A recovery mechanism based on implicit relaxation of constraints ensures that progress can again be made if the user is willing to compromise. Our empirical results show that progressive critiquing is most effective when users give priority to critiques on attributes whose values they are least inclined to accept.