http://www.touro.edu/library/GuidesTutorials/SearchTechniques.asp

Touro College Libraries

Search Techniques

Search tools (the online catalog, subject directories, search engines, etc.) are online indexes or databases. When you search an online index or database, you will have a better chance of success if you understand some fundamental search techniques.

Search techniques include the use of truncation, phrases in quotation, boolean logic, and field searching. The application of search techniques varies from database to database. Before you begin searching a database, take a few minutes to review any online HELP screens or guides so your queries will be constructed properly.

Truncation

Use truncation to retrieve variant word endings. It will broaden your search when you get too few results. Different resources use different symbols for truncating words, so read online HELP screens and guides.

Example: In some databases, teach* will retrieve teach, teacher, teaches, teaching, etc..

Phrases in quotation

Search for phrases by putting them within quotations. This technique has become a de facto standard.

Examples: "death penalty" "gun control" "special education" "cold war"

Boolean logic

The Web is a vast computer database, so it must be searched according to the rules of computer database searching. Much database searching is based on boolean logic.

Boolean logic refers to the relationship among search terms. It consists of three operators: OR, AND, and NOT.

OR broadens a search. It retrieves records with AT LEAST ONE term present. The more synonymous terms you combine, the more records you retrieve.

Example: college or university retrieves records that contain college, university, or both terms

AND narrows a search. It retrieves records with BOTH terms present. The more terms you combine, the fewer records you retrieve.

Example: poverty and crime retrieves records that contain both poverty and crime, not records with just one or the other

NOT narrows a search. It retrieves records with ONLY ONE term present. Be careful when you use NOT. The term you want may be present in documents that also contain the word you wish to avoid.

Example: cats not dogs retrieves records that contain cats and excludes records that contain dogs, and also those that contain cats and dogs

Go to the top of the page.

Boolean logic can appear in databases in three ways. It can involve full boolean with use of the operators. It can be implied with keyword searching. It can also be imbedded in predetermined language on a template or menu.

Full boolean uses OR, AND, NOT, and parentheses to force the order of processing. Parentheses keep semantically-related terms together as a logical unit.

Example: (international or global) and finance retrieves records that contain international, global, or both terms, then combines that result with records that also contain finance

Implied boolean uses symbols to represent boolean operators. The absence of symbols is also significant, as the space between keywords defaults to either OR or AND. This has become a defacto standard. Many resources that traditionally defaulted to OR are now defaulting to AND.

Example: cats felines could imply cats OR felines or cats AND felines. Read online HELP screens and guides to be sure.
Example: +dyslexia +adults implies AND and retrieves records with BOTH terms present.
Example: warfare -biological implies NOT and retrieves records with warfare and excludes records that contain biological, and also those that contain warfare and biological
Examples: criminal forensic +psychology could retrieve criminal OR forensic or criminal AND forensic (read online HELP screens and guides to be sure) AND combines that result with records that also contain psychology

Predetermined boolean uses a search template or menu from which you can choose boolean operators, usually with substitute language.

Example: Any of these words/Can contain the words/Should contain the words - means OR
Example: All of these words/Must contain the words - means AND
Example: Must not contain the words/Should not contain the words - means NOT

If available (read online HELP screens and guides to be sure), use a proximity operator (NEAR, etc.) to express an AND relationship between your terms. This will guarantee that your terms are found close to each other in the full text of the sources found. The closer your terms are placed, the more likely the search results will be relevant.

Examples: "poverty near crime" "dyslexia near adults"

Field searching

Field searching narrows a search. Use it to limit your results (by language, geography, date, etc.) when searching a large database with millions of full-text documents and files. The application of field searching varies, so read online HELP screens and guides.

Example: TITLE:acupuncture will produce fewer results than searching acupuncture as a keyword.

Use these search techniques when Finding Web Sites and ask your librarian for help if you need it. Then you can start Evaluating Web Resources to determine their appropriateness for research.

Go to the top of the page.