Abstract: A method of detecting and correcting an error in a string of information signals. When each information signal represents a word, the method detects and corrects spelling errors. The method detects and corrects an error which is a properly spelled word, but which is the wrong (not intended) word. For example, the method is capable of detecting and correcting a misspelling of "HORSE" as "HOUSE". In the spelling error detection and correction method, a first word in an input string of words is changed to form a second word different from a first word to form a candidate string of words. The spellings of the first word and the second word are in the spelling dictionary. The probability of occurrence of the input string of words is compared to the product of the probability of occurrence of the candidate string of words multiplied by the probability of misrepresenting the candidate string of words as the input string of words. If the former is greater than or equal to the latter, no correction is made.