28. The computer-readable storage medium of claim 21 , wherein the computer-readable instructions further cause the one or more processors to: determine, based on a distance of the contact motion from the first position to the second position, the probability that the contact input is an intended input to select the first key of the keyboard interface and the probability that the contact input is an intended input to select the second key of the keyboard interface.
21. A non-transitory computer-readable storage medium comprising computer-executable instructions, which when executed by one or more processors, cause the one or more processors to: detect a sequence of contact inputs via a keyboard interface on the touch-sensitive display, wherein detecting a contact input of the sequence of contact inputs comprises detecting an initiation of contact with the touch-sensitive display at a first position of the keyboard interface, a continuous contact motion from the first position to a second position of the keyboard interface, and a release of contact from the touch-sensitive display at the second position, and wherein the contact input represents a user selection of at most one character key of the keyboard interface; determine a plurality of candidate words corresponding to the sequence of contact inputs; rank the plurality of candidate words based on a probability that the contact input is an intended input to select a first key of the keyboard interface, and a probability that the contact input is an intended input to select a second key of the keyboard interface; and display a portion of the plurality of candidate words for user selection.