1 min readJul 31, 2018
- The average word length in English language is 4.7 characters.(http://norvig.com/mayzner.html). If you use maximum edit distance=5 for spelling correction then the algorithm would return (too) many spelling correction suggestions, which have nothing in common with the input word.
- For optimum spelling correction quality you have to find a compromise between recall (many suggestion) and precision (only suggestions which make sense). For English language this is a maximum edit distance between 2 and 3.
- In Peter Norvig’s tests 76% of spelling errors had an edit distance 1. 98.9% of spelling errors got covered with edit distance 2. https://web.archive.org/web/20120827064359/http://norvig.com/spell-correct.html
- The smaller you choose the maximum edit distance the faster the algorithm works, because less candidates need to be generated.
