... clusters for cat-egorial values, such as the attribute airline:They are clustered to a group of preferred air- lines, dispreferred airlines and airlines theuser does not-care about.4.2 Building ... value: business)2 arrival time, # of legs, departure time, travel time6 airline (preferred value: KLM)7 price, layover airportFigure 4: Attribute ranking for business userFigure 5: Option tree ... exper-iment was presented with six dialogue pairs, thefirst of which was used for training and was thusnot included in the analysis. Each dialogue pairconsisted of one dialogue between a user...