Limiters let you narrow the focus of your search so that the information retrieved from the databases you search is limited according to the values you select. You can use more than one limiter if more than one is available.
Common limiters that can appear below the Refine Search sub-tab include:
Full Text – Click to limit results to articles with full text.
Cover Story – Click to limit results to articles that were featured as cover stories.
Local Titles – Click to limit results to articles available at your library.
Journal/Magazine - Enter a journal/magazine name in this field to limit results to articles only from that title.
Peer Reviewed - Limits search results to articles from peer-reviewed journals. Peer-reviewed journals are publications that include only those articles that have been reviewed and/or qualified by a selected panel of acknowledged experts in the field of study covered by the journal.
Date Published - Use this option to search for articles within a specified date range. Create a range by using the drop-down lists to specify the months of the range and enter the last two digits of the year in the entry fields to specify the years of the range.
Number of Pages - Enter a number in this field to limit results to a specific number of pages in length. Place the < (less than) or > (greater than) symbol before the number to search for articles with a specific page length range. For example: to search for articles that are greater than three pages in length, enter >3 in this field. You can also use a dash to enter a range of pages. For example, to find articles between five and ten pages long, enter 5 - 10.
Limiters do limit one another. If you select both Full Text and Cover Story limiters, the results that are retrieved include only Full Text items that are Cover Story items. The exception to this rule is the use of Full Text and Local Titles limiters. In this situation, use of these limiters produces a list of results that has Full Text or is part of a local collection.
(The use of limiters may also vary by database. For example, MEDLINE may handle limiters differently than e-psyche.)
In the Find field, enter your search terms.
Select the limiter you want to use from the Limit Your Results section of the Refine Search sub-tab.
Click Search. The Result List appears.
Both database-specific limiters and global limiters are available to apply to your search term. When you search more than one database, the common limiters are displayed under the Limit Your Results heading. Other limiters may appear under the Special Limiters for: Database Name heading.
Limiters are applied to your search with the AND operator. When you make multiple selections from within a limiter (such as Publication Type or Language) those selections are applied with the OR operator. Limiters are applied to the entire search, and appear at the end of the search with the AND operator.
For example, if you perform a search and use limiters, the search is performed as follows:
search term and limiters
If you make multiple selections from the options available for a single limiter by pressing Control - Enter when searching from a list box, the search is performed as follows:
search term and ((one limiter or another limiter) and limiters)
For example: if you enter heart in the Find field, select the Full Text limiter, and select both Case Studies and Practice Guideline from the Publication Type limiter, the search is constructed as follows:
heart AND ((PT Case Studies OR PT Practice Guideline) and FT Y))
Advanced searches from your current session are saved and numbered, starting with S1. You can combine saved searches by entering them in the Find field - for example, S1 and S2. When you do, the limiters from each search are applied to the new search.
If S1 is a search for heart and (PT Case Studies or PT Practice Guideline) and S2 is a search for liver and kidney and FT Y, a search that combines S1 and S2 searches:
S1 and S2: ((heart) and (PT Case Studies or PT Practice Guideline)) and ((liver and kidney) and (FT Y))
S1 or S2: ((heart) and (PT Case Studies or PT Practice Guideline)) or ((liver and kidney (and FT Y))
In either case, the limiters from both searches are included.
Searches run from the Basic Search Screen are not saved to the History File used by the Advanced Search Screen. Lateral searches and searches launched from a record (via a link) are recorded to search history if the Advanced Search Screen is your starting point.
You can search using the limiters in the Advanced Search Screen without entering a term in the Find field. This lets you search very specific types of information like Review Articles, or certain Publication Types.
The limiters that are available depend on your selection of database, and they work to limit each other. For example, by selecting the Case Studies Publication Type and a date range, you could search your database for all Case Studies from 1999.
You can also search using field codes to qualify your search terms. By entering the appropriate field codes in the Find field, you could search, for example, for items by a specific author published in a particular year ((AU Smith) and (YR 99)). The search appears in the Add to Search column, and is assigned a Search ID number.
In the examples above, parentheses were used to show how searches are conducted by default in the Advanced Search Screen. Parentheses let you control a search query, and you can modify your searches by modifying their placement.
If you do not use parentheses, terms with AND and NOT have priority over terms with or. If you use parentheses, elements that are enclosed in parentheses are executed first, and those parentheses appear in Search History and in the Find field.
In the example below, the same search terms are used, but the use of parentheses modifies the search, and produces different results:
lung or ((kidney and liver) and skin) = 5912 results
(lung or kidney) and (liver and skin) = 9 results
Results for these searches differ according to the grouping of the terms.
If you do not use parentheses for the query, the order of operation for the Boolean operators is according to the Z39.50 standard. AND and NOT have priority over OR. For example, hockey or baseball and sports injuries will execute as:
hockey or (baseball and sports injuries)