1. In an automatic machine, a method of correcting incorrectly-spelled words in an object text stored in a memory wherein an incorrectly-spelled word is identified and a plurality of correctly-spelled candidate expressions is generated to replace said incorrectly-spelled word, which comprises: determining a probability function for each candidate expression, said probability function being based on both (1) a first stored probability of occurrence of said candidate expression in text independent of context and (2) a second stored probability of occurrence of the particular typographical modification that, when applied to said candidate expression, results in said incorrectly-spelled word, said first stored probability being computed from the number of occurrences of said candidate word in a large body of text in relation to the total number of words in said large body of text, said second probability being computed from the number of occurrences of said particular typographical modification in a training text containing known incorrectly-spelled words in relation to the total number of occurrences in said training text of the character or combination of characters modified by said particular typographical modification, and replacing said incorrectly-spelled word in said stored object text with the candidate expression having the highest probability function.