Search operators AND, OR, NOT, NEAR, and SAME may be used to combine terms in order to broaden or narrow retrieval.
Keep in mind that case does not matter when using search operators. For example, OR, Or, and or returns the same results. We use all uppercase in our examples as a matter of style.
Note: The Korean Journal Database does not include the SAME operator as a search operator.
This Help page includes information about the following topics.
Use AND to find records containing all terms separated by the operator.
Use OR to find records containing any of the terms separated by the operator.
Use NOT to exclude records containing certain words from your search.
Use NEAR/x to find records where the terms joined by the operator are within a specified number of words of each other.
Replace the x with a number to specify the maximum number of words that separate the terms.
If you use NEAR without /x, the system will find records where the terms joined by NEAR are within 15 words of each other. For example, these searches are equivalent:
Be aware that ...
You cannot use the AND operator in queries that include the NEAR operator. For example, the following query is not valid:
However, the NEAR operator may be used to find a word or phrase within X number of words of a phrase. The following queries are valid:
NEAR/0 dictates that the words joined by the operator should be adjacent.
When the Word NEAR Appears in a Title
Always enclose the word NEAR in quotation marks ( " " ) when the word appears in the title of a source item such as a journal, book, proceeding, or other type of work. For example, the following is a valid query.
If you leave out the quotation marks, the system returns an error message that states: "Search Error: Invalid use of NEAR operator"
In Address searches, use SAME to restrict your search to terms that appear in the same address within a Full Record. Use parentheses to group your address terms. For example:
Be aware that SAME works exactly like AND when used in other fields (such as Topic and Title fields) and when the terms appear in the same record. For example:
You can also use SAME when using the AB field tag when performing an Advanced Search of the Abstract. For example:
Search Operator Precedence
If you use different operators in your search, the search is processed according to this order of precedence:
Use parentheses to override operator precedence. For example:
copper OR lead AND algae finds all records in which both lead AND algae are present as well as all records in which the word copper is present.
(copper OR lead) AND algae finds all records in which the word algae is present together with either copper or lead.
Use of Parentheses
Use parentheses to override operator precedence. The expression inside the parentheses is executed first.
(cadmium AND gill*) NOT Pisces finds records containing both cadmium and gill (or gills), but excludes records containing the word Pisces.
(salmon OR pike) NEAR/10 virus find records containing salmon or pike within 10 words of virus.
Beverage AND bottle finds records containing both terms.
Beverage AND bottle AND beer finds records containing all three terms.
Implied AND Operator
The product uses an implicit AND operator when you enter two or more adjacent terms in most fields.
For example, the title search rainbow trout fish farm is equivalent to rainbow AND trout AND fish AND farm -- both queries return the same number of results.
Note: Implied AND does not apply to Chinese-language search queries.
Beverage OR bottle finds records containing either beverage or bottle (or both).
Beverage NOT bottle finds records containing beverage but excludes records containing bottle.
Beverage NEAR/5 bottle finds records containing both beverage and bottle. The two words must be within five words of each other.
Mineral Resources SAME Beijing finds records containing an author address in which the terms Mineral Resources and Beijing both appear within the Adddress field of a record.
About SAME and Saved Searches
When you open a search history file created from a previous version of the product, your search may yield more results if you had used the SAME operator in your query. In the current version, the SAME operator works exactly like AND in most fields (such as the Topic and Title fields).
For example, the search query:
TS=Bird Migration SAME TS=South America*
Is automatically translated in the current version of the product into:
TS=Bird Migration AND TS=South America*
and produces a larger set of search results than the original query.
When opening a saved search history file from a previous version of the product, consider revising your query if you had used the SAME operator in the query.
Note: The exception to the rule discussed, here, is the Address field where SAME operator rules still apply.