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General Searching InstructionsBoolean
Operators | Quotation
Marks | Complex Queries with Multiple Boolean Operators The information on this page will help you to understand the basic concepts involved in searching for documents on GPO Access. It contains general instructions, covering topics such as how to construct a query and how to interpret a results list. For specific instructions on how to use a particular database, as well as sample searches, please consult the Search Tips for that database. Search Tips are available from the main search page for each database and from the GPO Access Databases page. For information about file formats, see GPO Access File Formats. Boolean OperatorsBoolean operators (AND, OR, NOT, and ADJ) establish logical relationships among concepts expressed in a query. In other words, they are used to make searches more specific. The more specific your search is, the fewer number of extraneous hits you will receive.
[ Top ] Quotation MarksQuotation marks have a function equivalent to that of the ADJ Boolean operator within a search query. Thus, the queries "Government Printing Office" and Government ADJ Printing ADJ Office return the same results. You may use quotation marks in combination with Boolean language. [ Top ] Complex Queries with Multiple Boolean OperatorsComplex queries may be constructed with multiple Boolean operators. For clarity, parentheses should be used to group sections of the query and to ensure that the WAIS server parses the query as intended.
If the above example lacked parentheses, the WAIS server would process the phrases first, the AND operators next, and the OR operators last. The resulting query would be read by the server in the following manner:
A test of these searches in the 1998 Federal Register database retrieved 22 documents for the first query and 679 for the second, which demonstrates the importance of using parentheses for complex queries. [ Top ] TruncationThe asterisk (*) may be used to truncate words in a query in order to expand a search within a specified range. For example, a search for librar* will return documents that contain the word(s) "library," "library's," "libraries," "librarian," etc. Using truncation saves you time by eliminating the need to perform different searches for variations on a single word that differ only in their endings, or suffixes. When constructing a truncated query, try to include as many characters from the desired words (or phrases) as possible in order to reduce the number of irrelevant documents returned.
[ Top ] StopwordsStopwords, such as "the" and "it," are words that occur so frequently in documents that they are not useful for distinguishing one document from another. Since they are not indexed, they cannot be used in searches. Therefore, stopwords that are included in queries are ignored by the system. For example, the query "National Council on Disability" returns the same documents as the queries "National Council Disability" and National ADJ Council ADJ Disability. A comprehensive list of GPO Access stopwords follows:
[ Top ] Maximum ResponsesThe maximum responses you may receive from a query is set at a default of 50. To locate a larger number of documents, you must change the setting. All of the GPO Access search pages provide a pull-box in which you may change the maximum number of returned documents up to a limit of 200. Generally, 50 responses should be adequate to retrieve the document for which you are searching. If you cannot find a desired document with the default 50 responses, you may want to try making your query more specific before expanding the number of returned documents. Keep in mind that, by increasing the number of documents to be retrieved, you are also increasing the time that it takes to return your search results. [ Top ] Relevance Ranking and Document ScoreSearch results are displayed in an order that is determined by a system called relevance ranking. The most "relevant" document appears at the top of your results list with a score of 1,000; the least "relevant" appears at the bottom of the list with a score of one. As a general rule, document scores should decrease gradually from the top to the bottom of your results list. Typically, documents with a score of less than 500 are not very "relevant" to your search and are not worth retrieving, unless you are fairly certain of their contents and their significance to your topic. "Relevance" is computed based on the following five factors:
[ Top ] Identification CodesThe WAIS server generates an identification code that is unique to each database on GPO Access. The sole purpose of this identification code is to identify the database from which a particular document is retrieved. You can find a database identification code to the left of a document's title in your search results list. Although identification codes usually are not terms residing in the text of a document and, as a result, are not searchable, they are useful for differentiating among dates, sections of a single database, and, in the case of more complex searches, documents from multiple databases. To learn more about the identification codes for a particular database, consult the Search Tips for that database. [ Top ] Document SizeA document's size (in bytes) is listed below its title in your search results list. The size applies to the ASCII text file of that document. If another type of file, such as a PDF file, is available for the same document, it will typically be larger. Please keep this generalization in mind when you are attempting to download large documents. [ Top ] 1,000-Point DocumentsIn addition to identifying the document most "relevant" to your search, 1,000-point documents are used occasionally to alert you to structural database enhancements. Whenever two 1,000-point documents appear in your results list, the first is an online message from GPO and the second is the 1,000-point document that applies to your query. These messages, in the form of a returned document, may give the status of periodic database upgrades and enhancements; announce new databases, applications, and features; state when a database is expected to be back online; or supply other information deemed important for users of that database. They do not interfere with the results of your search. [ Top ] Query ReportsA query report always appears as the final document with a score of one in your search results list. This document contains information on how your query was parsed, the fields and number of documents in the database you searched, the number of words in the database that conformed to your search request, the total number of relevant documents identified, and the speed of retrieval. [ Top ] |