18. The method of claim 1 , wherein determining the first group of points on the presence-sensitive display traversed by the first sub-gesture is based at least in part on one or more of: a length of a segment associated with the first sub-gesture, wherein the segment comprises a path traversed by the first sub-gesture at the presence-sensitive display; a direction of movement associated with the segment of the first sub-gesture; a curvature of the segment of the first sub-gesture; a local speed that represents a rate at which the segment of the first sub-gesture is detected; and a global speed that represents a rate at which the first sub-gesture is detected.
18. The method of claim 1 , wherein determining the first group of points on the presence-sensitive display traversed by the first sub-gesture is based at least in part on one or more of: a length of a segment associated with the first sub-gesture, wherein the segment comprises a path traversed by the first sub-gesture at the presence-sensitive display; a direction of movement associated with the segment of the first sub-gesture; a curvature of the segment of the first sub-gesture; a local speed that represents a rate at which the segment of the first sub-gesture is detected; and a global speed that represents a rate at which the first sub-gesture is detected. 19. The method of claim 18 , wherein determining the at least one probability that the at least one key included in the at least one of the first and second groups of keys is associated with at least one of the first sub-gesture and the second sub-gesture comprises: determining a first probability that the at least one key is included in the first group of keys associated with the first sub-gesture; determining a second probability that the at least one key is included in the second group of keys associated with the second sub-gesture; if the first probability is greater than the second probability, determining that the at least one key is included in the first group of keys; and if the second probability is greater than the first probability, determining that the at least one key is included in the second group of keys.