The Goddard Library Repository uses Lucene as its indexing and search software.  You can perform simple searches or invoke the advanced search to refine your results.  Search terms are not case sensitive and, although truncation is supported by wildcard symbols (see below), word stemming is not the default.  Results are ranked and displayed based on the number of times the search terms appear in the record.  The results are initially displayed as a listing of brief record.  Click on the title in the hitlist to retrieve the full record.


Simple Search 

Enter one or more words in the search box to search the indexed fields of the record

     Example:  management

Note: When searching for more than one word, the words are combined with OR by default. For example, a search for project management, will produce results with either the word project or management in the records


Exact Phrase Search 

To match your search phrase exactly, surround it with quotes

     Example:  "project management"


Boolean Search

If your search yields too many results, you can use Boolean  operators (AND, OR, NOT) to refine your results.  The Boolean operator must be typed in all uppercase or capital letters.

OR: If you want to search for documents that contain either the words "A" or "B" use the OR operator. This is helpful when searching for synonyms. Keep in mind that if you don't put any Boolean operator between two search words, the OR operator will be added between them automatically.

     Example: lunar OR moon and lunar moon both search for records containing either lunar or moon.

AND: If you want to search for documents that contain more than one word use the AND operator. For example, project AND management returns all records that contain both project and management in any order.

     Example:  "risk management" AND "launch decision"

NOT: If you want to eliminate records that contain certain words use the NOT operator.  Documents that contain the search word immediately after the NOT operator won't be retrieved.
For example, if you want to search for records that contain the word project but not management you may use the query project NOT management.

     Example:  "risk management" NOT "launch decision"


Field Search

You can also limit the search to specific fields. The searchable fields are the fields that are indexed for the specific collection. They include the title, author or creator, contributor, abstract or description, subject, subject keyword, and other fields.

     Example:  keyword:"launch decision"

You can also combine a field search with a Boolean search for more precision.

     Example:  keyword:"launch decision" AND "risk management"

If you need help constructing field and Boolean searches, you can use a collection's Advanced Search.  The Advanced Search searches for words or phrases in a specific field or combination of fields and provides drop-down menus of fields and Boolean operators to construct more specific searches.


Wildcard Searches

Wildcards provide a mechanism for performing variable searches.  The two wildcard symbols are the asterisk (*) and the question mark (?).  Use the asterisk (*) to match 0 or more characters of any kind, and the question mark (?) to match 0 or 1 character of any kind.  Please keep in mind that wildcards cannot appear at the beginning of a search term.

     Example:  manag* matches manage, manager, management, managing, etc.
     Example:  astro*y matches astronomy, astrobiology, etc.

     Example:  te?t matches test, text, tent, etc.


Fuzzy Searching

If you are unsure how to spell something, a fuzzy search is a good option.  You can invoke a fuzzy search using the tilde (~) operator to search for the words that are similar in spelling and structure.  Keep in mind that you may get unexpected results. 

     Example:  Braye~ matches Brahe, Braun, brain, braze, etc.

Note: a fuzzy search will pick out words structurally similar to the search term, regardless of meaning.  Synonyms will not be searched.