When you type a word or phrase into a search engine, there are a number of things that could go wrong. You might not know how a term is spelled or, in your rush to jump to the results, you could transpose or otherwise mistype some characters. Spelling alteration is a popular search technique used to translate apparent typographical errors, alternative spellings, and synonyms into an improved query that returns the best possible results on the first try. But this approach is not without its pitfalls. You might enter a word correctly that's not widely used but has a neighbor in the dictionary that's much more popular on the Internet. One person's spelling error could be another's perfect query. Which results should the search engine provide, and how should any useful alternative searches be represented?  To read more click here