Article révisé par les pairs
Résumé : The paper presents all the families of semiorders and interval orders that can be built up on the basis of some valued preference relations., Some of these families (called row and column-homogeneous) generalize the homogeneous families of semiorders studied by Roberts and include the {Pλ} families studied by Fishburn. The families are then examined from the view point of interval representation models, also called "threshold models".