If you use the following between keywords, you will find websites that have either of the keywords:
Jump to: Metadata Field Operators │ List of Common Field Operators │ List of Collection Codes │ Searching MODs Metadata Search Query OperatorsBecause queries can be very complex and can use several different operators, there needs to be a way to evaluate expressions unambiguously. This is done through the use of operator precedence, which is a way of specifying which operators and expressions are evaluated first, second, and so on. In the list below, the precedence of the operators is from first to last.
The sections that follow will show you how to use a variety of characters and operators to narrow your search. SpacesA space is used to separate words or operators in a search query. In a simple query where operators are not used, spaces between words are treated as an implied "and" so that the search results will contain documents containing all of the words that have been entered. Note: In certain cases, the search engine will automatically assume that two terms separated by a single space should be treated as a single phrase to increase the accuracy of results. This primarily occurs with proper names. For complex queries using operators, the following should be noted:
Example To search for only those documents that contain both the words Bill and Clinton, you can enter Bill Clinton into the Search Box and click the Search button. The search engine will look for both words in the document and return those documents where both words can be found anywhere in the document. Quotation MarksQuotation marks tell the search engine to return documents if and only if they contain the exact phrase or string of words between quotes. Examples
Boolean OperatorsA Boolean search is a search that uses the logical (i.e., Boolean) operators (AND, OR, NOT, -) in addition to the keywords.
Note: Boolean operators are not case sensitive. For example, entering and or AND will return the same results. Examples
Proximity OperatorsProximity Operators allow you to specify searches where one word is near, next to, or in the vicinity of another word. The three proximity operators defined are:
Examples
Note: Because a proximity expression is trying to find words (or phrases with quotes) that are located within a specified proximity of each other, using Boolean operators or multiple words without quotes in a proximity expression will result in a search query error. One way to make sure that you do not get search query errors is to always use parentheses around the proximity expression when creating search queries that use proximity operators. Examples of proximity expressions using quotes:
ParenthesesParentheses are used to group words and expressions so that the result of evaluating the expression between the parentheses can be used as part of a more complex query. The use of parentheses is recommended to isolate expressions in your query from other expressions, especially when creating complex queries using proximity operators and field operators. Examples
Number of HitsThe Number of hits "+" operator can be used to specify that documents with more hits on a particular word be given preference over documents with hits on other words. Examples
Wild CardsWild cards can be used as substitutions for one or more characters in a search term
Examples
Metadata Field OperatorsField operators are operators that represent metadata fields. Using field operators tells the search engine to retrieve documents where the value of the metadata field is equal to the value given in the field operator expression. Searches with field operators are useful when you know the values of descriptive data (metadata) such as titles, sponsors, and dates. Range is used to specify the set of all values a query should return.
When using field operators, you must observe the following rules:
Examples
The table below lists commonly used field operators that apply to all or most of the collections. Lists of collection-specific metadata field operators are available under the What's Available section. Common Field Operators for Most Collections
Collection Codes
Searching MODS MetadataMODS is a metadata standard that includes information about a digital object. It stands for Metadata Object Description Schema and the standard is maintained by the Library of Congress. You can perform a search over any field in the MODS metadata. Examples:
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