Reconstructing what happened to create a given typo. For instance, if someone types "dpg," when they mean "dog," it makes sense, since "P" is right next to "o" on a qwerty
"6he" could also be a variant of "the."
"qinteresting" means that the user accidentally hit the "q" key with their left hand when beginning to type "interesting."
"afewwdaewf" means that the user has had a stroke in the right hemisphere of the brain.
";jlkjkl;o;lkj;" means that the user has had a stroke in the left hemisphere of the brain.