14. A non-transitory computer-readable storage medium encoded with instructions that, when executed, cause at least one processor of a computing device to: output, for display at an output component operatively coupled to the computing device, a graphical user interface that includes a text edit region and a graphical keyboard; receiving an indication of a first input detected at a first location of a presence-sensitive input component operatively coupled to the computing device, wherein the first location of the presence-sensitive input component corresponds to a region of the output component at which the graphical keyboard is displayed; determine, based at least in part on the indication of the first input, a new character string that is not included in a language model of the computing device; add, to the language model, the new character string and a corresponding likelihood value associated with the new character string; responsive to receiving an indication of a second input detected at a second location of the presence-sensitive input component, wherein the second location of the presence-sensitive input component corresponds to the region of the output component at which the graphical keyboard is displayed; predict, based on the indication of the second input and the likelihood value associated with the new character string, the new character string and an input context associated with the second input; responsive to predicting the new character string, output, for display within the text edit region, the new character string; receive an indication of a third input detected at a third location of the presence-sensitive input component, wherein the third location of the presence-sensitive input component corresponds to the region of the output component at which the graphical keyboard is displayed; and responsive to determining that the third input deletes the new character string from the text edit region after being output for display: remove, from the text input region, the new character string; and decrease, at a rate or magnitude that is adapted to the input context, the likelihood value associated with the new character string without removing the new character string from the language model.
14. A non-transitory computer-readable storage medium encoded with instructions that, when executed, cause at least one processor of a computing device to: output, for display at an output component operatively coupled to the computing device, a graphical user interface that includes a text edit region and a graphical keyboard; receiving an indication of a first input detected at a first location of a presence-sensitive input component operatively coupled to the computing device, wherein the first location of the presence-sensitive input component corresponds to a region of the output component at which the graphical keyboard is displayed; determine, based at least in part on the indication of the first input, a new character string that is not included in a language model of the computing device; add, to the language model, the new character string and a corresponding likelihood value associated with the new character string; responsive to receiving an indication of a second input detected at a second location of the presence-sensitive input component, wherein the second location of the presence-sensitive input component corresponds to the region of the output component at which the graphical keyboard is displayed; predict, based on the indication of the second input and the likelihood value associated with the new character string, the new character string and an input context associated with the second input; responsive to predicting the new character string, output, for display within the text edit region, the new character string; receive an indication of a third input detected at a third location of the presence-sensitive input component, wherein the third location of the presence-sensitive input component corresponds to the region of the output component at which the graphical keyboard is displayed; and responsive to determining that the third input deletes the new character string from the text edit region after being output for display: remove, from the text input region, the new character string; and decrease, at a rate or magnitude that is adapted to the input context, the likelihood value associated with the new character string without removing the new character string from the language model. 18. The non-transitory computer-readable storage medium of claim 14 , wherein each of the first and second inputs comprise at least one of a discrete tap gesture or a portion of a continuous gesture.