Section 8.6. Query Builders

8.6. Query Builders

Besides search algorithms themselves, there are many other means of affecting the outcome of a search. Query builders are tools that can soup up a query's performance. They are often invisible to users, who may not understand their value or how to use them. Common examples include:

Spell-checkers

These allow users to misspell terms and still retrieve the right results by automatically correcting search terms. For example, "accomodation" would be treated as "accommodation," ensuring retrieval of results that contain the correct term.

Phonetic tools

Phonetic tools (the best-known of which is "Soundex") are especially useful when searching for a name. They can expand a query on "Smith" to include results with the term "Smyth."

Stemming tools

Stemming tools allow users to enter a term (e.g., "lodge") and retrieve documents that contain variant terms with the same stem (e.g., "lodging", "lodger").

Natural language processing tools

These can examine the syntactic nature of a queryfor example, is it a "how to" question or a "who is" question?and use that knowledge to narrow retrieval.

Controlled vocabularies and thesauri

Covered in detail in Chapter 9, these tools expand the semantic nature of a query by automatically including synonyms within the query.

Spell-checkers correct for an almost universal problem among searchers and are well worth considering for your search system. (Look over your site's search logs, and you'll be amazed by the preponderance of typos and misspellings in search queries.) The other query builders have their pros and cons, addressing different information needs in different situations. Once again, a sense of your users' information needs will help you select which approaches make the most sense for you; additionally, keep in mind that your search engine may or may not support these query builders.