We consider example-critiquing systems that help people search for their most preferred item in a large electronic catalog. We analyze how such systems can help users in the framework of four existing example-critiquing approaches (RABBIT, FindMe, Incremental Critiquing, ATA and AptDecision). In a second part we consider the use of several types of explicit passive analysis to guide the users in their search, specially in either underconstrained or overconstrained situations. We suggest that such a user-centric search system together with the right explicit passive analysis makes the users feel more confident in their decision and reduces session time and cognitive effort. Finally we present the result of a pilot study.