Search Engine Glossary

Boolean search: A search allowing the inclusion or exclusion of documents containing certain words through the use of operators such as AND, NOT and OR.

Concept search: A search for documents related conceptually to a word, rather than specifically containing the word itself.

Full-text index: An index containing every word of every document cataloged, including stop words (defined below).

Fuzzy search: A search that will find matches even when words are only partially spelled or misspelled.

Index: The searchable catalog of documents created by search engine software. Also called "catalog." Index is often used as a synonym for search engine. Index is commonly pluralized as "indices." However, Search Engine Watch instead uses the alternative plural form "indexes."

Keyword search: A search for documents containing one or more words that are specified by a user.

Phrase search: A search for documents containing a exact sentence or phrase specified by a user.

Precision: The degree in which a search engine lists documents matching a query. The more matching documents that are listed, the higher the precision. For example, if a search engine lists 80 documents found to match a query but only 20 of them contain the search words, then the precision would be 25%.

Proximity search: A search where users to specify that documents returned should have the words near each other.

Query-By-Example: A search where a user instructs an engine to find more documents that are similar to a particular document. Also called "find similar."

Recall: Related to precision, this is the degree in which a search engine returns all the matching documents in a collection. There may be 100 matching documents, but a search engine may only find 80 of them. It would then list these 80 and have a recall of 80%.

Relevancy: How well a document provides the information a user is looking for, as measured by the user.

Search Engine: The software that searches an index and returns matches. Search engine is often used synonymously with spider and index, although these are separate components that work with the engine.

Spider: The software that scans documents and adds them to an index by following links. Spider is often used as a synonym for search engine.

Stemming: The ability for a search to include the "stem" of words. For example, stemming allows a user to enter "swimming" and get back results also for the stem word "swim."

Stop words: Conjunctions, prepositions and articles and other words such as AND, TO and A that appear often in documents yet alone may contain little meaning.

Thesaurus: A list of synonyms a search engine can use to find matches for particular words if the words themselves don't appear in documents.

More Resources

Search Engine Lingo
SearchDay, Dec. 16, 2002

The world of search has its own specialized language that can be intimidating at times, but these glossaries offer definitions and examples that will get you speaking the lingo in no time.

Search Engine Terms

Available in English and other several other language, this is a list of terms compiled by readers of the I-Search mailing list. It is especially oriented toward search engine marketing terms.

Glossary for Information Retrieval˜weiss/glossary.html

Scott Weiss provides an expanded list of terms and more technical definitions relating to search engines and information retrieval.

Confused by marketing jargon? Here's a guide to common terms in different categories, including search engine marketing.