1. A method comprising: outputting, by a computing device and for display, a graphical user interface including a graphical keyboard and one or more text suggestion regions, wherein at least one character string is displayed within the one or more text suggestion regions, the at least one character string being associated with a probability; receiving, by the computing device, an indication of an initial gesture input detected at a presence-sensitive input device operatively coupled to the computing device; maintaining, by the computing device, based on the initial gesture input, past user interaction data to reflect a past decision corresponding to the at least one candidate character string while the at least one candidate character string was previously displayed within the one or more text suggestion regions; receiving, by the computing device, an indication of a subsequent gesture input detected at the presence-sensitive input device operatively coupled to the computing device; determining, by the computing device and based at least in part on the indication of the subsequent gesture input, the at least one candidate character string; determining, by the computing device and based at least in part on an association between the at least one candidate character string and a context of the subsequent gesture input, a lexical probability for the at least one candidate character string, the lexical probability indicating a probability that the at least one candidate character string represents a word included in a lexicon; modifying, based at least in part on the past interaction data, the lexical probability; and outputting, by the computing device, for display, based on the lexical probability that was modified based at least in part on the past interaction data, the at least one candidate character string.