A method for classifying multiple touch contacts with a touch sensitive surface , the method comprising: receiving frame data representing multiple touch contacts with the touch sensitive surface , wherein touch intensity values are assigned to positions of contact; performing a subdivision analysis, wherein the frame data is divided into subdivisions, and the subdivisions are demarcated in a variety of bounding area shapes, and wherein the subdivision analysis is performed on descriptive features for each subdivision of the frame data to determine whether the results of the subdivision analysis of each subdivision are consistent with the pattern classification for the multiple touch contacts, according to the descriptive features and the location of the subdivision; performing a pattern classification to discriminate between different types of multipoint contacts based on a pattern of the multiple touch contacts, wherein the different types of multipoint contacts include multipoint finger or palm contacts or multipoint head contacts, and wherein the pattern classification is based on touch intensity and on an object type criteria in order to distinguish the magnitude of the amplitude intensity of the multipoint contact with respect to the different types of multipoint contact, wherein the object type criteria is determined at least in part by using vibro-acoustic data from mechanical vibration generated by the multipoint contact; if the results of the subdivision analysis are consistent with the pattern classification to result in a frame contact classification for the multiple touch contacts with the touch sensitive surface according to the descriptive features, determining an event based on the frame contact classification; and if the results of the subdivision analysis are inconsistent with the pattern classification, obtaining and analyzing a subsequent frame data. receiving frame data representing multiple touch contacts with the touch sensitive surface , wherein touch intensity values are assigned to positions of contact; performing a subdivision analysis, wherein the frame data is divided into subdivisions, and the subdivisions are demarcated in a variety of bounding area shapes, and wherein the subdivision analysis is performed on descriptive features for each subdivision of the frame data to determine whether the results of the subdivision analysis of each subdivision are consistent with the pattern classification for the multiple touch contacts, according to the descriptive features and the location of the subdivision; performing a pattern classification to discriminate between different types of multipoint contacts based on a pattern of the multiple touch contacts, wherein the different types of multipoint contacts include multipoint finger or palm contacts or multipoint head contacts, and wherein the pattern classification is based on touch intensity and on an object type criteria in order to distinguish the magnitude of the amplitude intensity of the multipoint contact with respect to the different types of multipoint contact, wherein the object type criteria is determined at least in part by using vibro-acoustic data from mechanical vibration generated by the multipoint contact; if the results of the subdivision analysis are consistent with the pattern classification to result in a frame contact classification for the multiple touch contacts with the touch sensitive surface according to the descriptive features, determining an event based on the frame contact classification; and if the results of the subdivision analysis are inconsistent with the pattern classification, obtaining and analyzing a subsequent frame data. <EOS>