Basic Tips for Boolean Searching
1. Begin with a simple search.
Keep search expressions simple. Start with two or three keywords, like "landlord" and "deposit." If the search produces too many results, try adding another keyword, perhaps "landlord" and "deposit" and "damages," to focus the search and narrow the range of hits. When formulating a search expression, consider:
- the facts of the case;
- the cause of action or legal principle; and
- the remedy to be illustrated.
2. Use caution with terms that might narrow research.
Certain keywords can narrow results inappropriately. If a search appears to return fewer documents than expected, one or more keywords might be limiting the hits. Try omitting a keyword, or replace it with a more general synonym.
For example, the word 'automobile' might limit search results in many contexts; try using 'automobile or vehicle or car or truck' instead, and group the search criteria as follows.
(automobile or vehicle or car or truck) and dr?nk*
Note the use of the wildcard and expander: dr?nk* retrieves 'drunk,' 'drunken,' 'drink,' 'drinking,' etc. Depending upon results, try another search and substitute 'intoxication' for 'dr?nk*'. The related word 'intoxication' might broaden the number of hits or vary the list of relevant results.
3. Search specific fields whenever possible.
Searching fields—as opposed to searching the entire text—may improve results. If possible, search more than one field at a time.
For example, if users know the date range and subject matter of a case in advance, the following fields on a case law Search Page might produce the best results:
Date Range: between |01| |01| |1990| AND |12| |31| |1999|
Text of Majority Opinion = landlord and deposit and damages
Note that the Search Entire Document field may be combined with any other field. The sample search above could be expanded to find the same keywords in a dissenting or concurring opinion (in addition to the majority opinion), as follows:
Search Entire Document = landlord and deposit and damages
Date Range: between |01| |01| |1990| AND |12| |31| |1999|
4. When searching for proper names, use the near connector.
Proper names—for example, the names of appellants or judges, or the names of buildings and landmarks—often appear inconsistently in the law. For example, some jurisdictions use middle initials in reference to judges, whereas others use the judges' full names. Still others might use first and middle initials only. To cover the range of options, use the 'near' connector when searching for names. For example, type "william near3 johnson" to find "William P. Johnson," "William Paul Johnson," "Johnson, William P.," and other variations. For more discussion on connectors, see Connectors and Multiple connectors, parentheses, and search priority.
5. Narrow the search criteria if results are too numerous.
If a search returns too many documents, the search criteria are probably too broad. To narrow the search:
- add another keyword using the 'and' or 'not' connector;
- exchange one or more keywords with a more narrow synonym;
- replace the 'and' connector with 'near' (or 'nearx');
- exclude a common or broad keyword using the 'not' connector; or
- enter search criteria in multiple fields.
Loislaw also offers Search Within a Search, a special tool for narrowing a body results. See Search Within a Search for more details.
6. Expand the search criteria if results are too few.
If a search returns too few documents, the search criteria are probably too narrow. To broaden the search:
- add an expander (' * ') to find more variants of a keyword;
- use a broader synonym in place of a keyword;
- search for a specific phrase using quotation marks; or
- remove a keyword.
7. If phrase searching produces too few (or no) results, use the 'near' connector.
Phrases generally known to exist in the law may not always be retrieved by phrase searching. Insert the 'near' connector between words in a phrase to retrieve different variants. For example, the search phrase 'child custody' finds only the text "child custody". The search phrase 'child near4 custody' finds "the mother had custody of her child" as well as "child custody". For more information on connectors and phrase searching, see Connectors and phrase searching with quotation marks.