Note that multilingual sites must be very careful in implementing the correct stemming algorithm for each page's languages, or they may return some very odd results. Adding metadata to pages can help match search words, especially for broader and narrower terms. If you have pages describing DSL and cable modems but never use the word broadband , adding that term to the META Keywords tag content will allow the search engine to find those pages Search engines may allow search administrators to set up synonym lists or thesari to provide appropriate alternate terms. For direct synonyms, such as urticaria as the technical term for hives , it's appropriate to simply add that to the query. For less obvious equivalents, such as red for crimson , and for broader and narrower terms, the search engine should display them and allow the searcher to click on them rather than typing them in.
People make mistakes in spelling all the time.
For simple typos, log file analysis shows that searchers will re-enter the word correctly. However, they often are unable to remember unfamiliar terms such as diseases, product codes, and names in general. A spellchecker can provide a list of correctly-spelled words, allowing searchers to switch to the right spelling. Complex Solutions Information Retrieval theorists have come up with some clever solutions to spelling errors, but they can be frustrating to users unless presented properly. Fuzzy matching techniques try to reduce words to their core and then match all forms of the word.