Searching

Searching the Basic Indexes 
The Search field at the top of the screen is a great place to start your search, and in many cases, may be the only field you need to use to find your information. It provides a high-level search through all the basic index fields for the term you enter with just one step.  If you're not sure what fields are in the Basic Indexes, click the question mark () next to the Search field. In the MEDLINE database, the help returned the following information:  top 

Logical Operators 
Notice that logical operators (AND, OR, NOT) can be used in your search string in this field and in all text fields. (Later, you'll see how you can create the same search strategy by modifying a search and using the Narrow, Widen or Exclude buttons.) 

Note: You can also use logical operators in indexed fields when indexed terms are enclosed in quotes. For example: "CARS" AND "GAS". 

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Wildcard 
When using multiple terms in a search strategy, the order of search is from left to right unless parentheses are used, in which case the operations inside the parentheses are performed first. The wildcard character, a question mark (?), can also be used to find variations of a root word. 

For example, entering COMPUT? retrieves records for COMPUTER, COMPUTERS, COMPUTING, and COMPUTATION. 

This truncation symbol can only be used at the end of a root term, not at the beginning or embedded in the term. For example, ?GUARD or COL?R are not valid search terms. 

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Proximity Search 
In addition, you can use periods for adjacency in your search terms. For example, MINI...CARS, where the term CARS follows within three words of the term MINI. Remember the search goes from left to right. Therefore, this search would retrieve MINI VANS AND SPORTS CARS, but not SPORTS CARS AND MINI VANS. 

Executing the Search 
To search for a term, enter it in the Search field and click the green Search button. The following example shows searching for the term, melatonin, in the MEDLINE database.  This request searches the Title, Abstract, Tags, Descriptors, Named Person, CAS Registry No., Enzyme No., and Gene Symbol fields (all fields included in the Basic Index) for the term melatonin. It returns a summary of the results in the Search History box when the search is completed. 

In this example, the search resulted in 25 records.  At this point, you can display the records or modify your search. Both tasks are discussed in detail later in this section. 

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Searching an Index Field 
In the Basic Index search example, the term melatonin was searched for in the Title, Abstract, Tags, Descriptors, Named Person, CAS Registry No., Enzyme No., and Gene Symbol fields and resulted in a set of 25 records. 

Targeting a specific field, such as the Title or Subject Headings fields, will typically result in fewer, but possibly more applicable records. In the following example, the blue index button after Select Subject Headings provides an option for you to select the term (or terms) you want directly from the index of subject headings.  Type in all or a portion of the term and click the blue index button. The screen updates with the position of the index where the term you entered is located.  Browsing in ZZ refers to the field name that is assigned to the index you searched. The right and left arrows let you move forward and back through the index to look at additional terms. You can also enter a new term in the Jump To field to move to a different area of the index by selecting the Jump To button. 

The first line shows that 25 records are indexed with the term melatonin. If you want to select all 25 records, highlight the line and click the green Search button located at the bottom left of the screen. 

However, if you want to narrow your search, you can browse through the index and view the term broken down by its subheadings, such as ADVERSE EFFECTS. To retrieve a set of records, click on the lines containing the information you want and click Search. 

Several databases, like MEDLINE, contain a thesaurus that suggests related terms you may want to include in your search. In the previous example, the results show that the term melatonin has 4 related terms. To view them, click the line of the related term you want to highlight it and then click Related at the bottom of the screen. Alternately, you can highlight None and click Search to return to the main search screen.  This example shows that there were 5 related terms for FREE RADICAL SCAVENGERS and 14 related terms for TRYPTAMINES.  Notice that after the related term, there is a note in parentheses, such as (Related), (Narrower) or (Broader). This note indicates the type of relationship between your search term (MELATONIN) and the related terms (FREE RADICAL SCAVENGERS or TRYPTAMINES). 

To select a set of records, highlight the lines indicating the records you want to retrieve and click Search. To select additional related terms, highlight them and click Related. Alternately, you can highlight None and click Search to return to the main search screen. 

Searching a Text Field 
A text field provides for more complex searches using logical operators (AND, OR, NOT), and specifying the order and proximity. The following example demonstrates searching for records containing the terms Seasonal Affective Disorder (or disorders).  The question mark () wildcard searches for all words with the root word disorder, retrieving disorder, disorders, etc. The two periods stipulate that the term disorder (or disorders) can be within two words after the term, seasonal.  This Search History box shows that 5 records were found in the Subject Heading index where the term disorder(s) was within 2 words of term seasonal. 

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Modifying a Search 
When at least one set of records has been created, there are several options available to modify your search results. 

Three options (color coded with green buttons) let you modify a set of records with additional terms that will either: 

• Narrow your latest set of search results to include the term(s) in your first set AND the additional term(s) you enter. 
• Widen your latest set of search results to include the term(s) in your first set OR the additional term(s) you enter. 
• Exclude the additional term(s) you enter from your latest set of search results. The results will include the term(s) in your first set, but NOT the additional term(s) you enter.

• Intersect combines your search results to include the terms used in Set1 AND Set2 AND Set3, for however many sets you highlight. 
• Union expands your search results to include the terms used in Set1 OR Set2 OR Set3, for however many sets you highlight. 

Narrow a Search 
If a search retrieves too many results, you can refine it by adding another search term. For example, to modify the MELATONIN search results to include only the records that are about melatonin AND its use for helping people sleep, use the following steps: 

1. Highlight the first set you created with the search for melatonin. 
2. Enter sleep? in the Enter Word(s) to search field to retrieve sleep, sleeping, as well as other words using the same root. 
3. Click Narrow and a new set is created containing the terms melatonin AND sleep in the record. The Search History box updates with the new search results showing that 6 records now remain in Set 3. 
 

Widen a Search 
If you want to expand your search to include other terms, use the Widen option. For example, to modify the melatonin search results in Set 1 to include the term melatonin OR the term sleep?, use the following steps: 

1. Highlight the first set you created with the search for melatonin. 
2. Enter sleep? in the Enter Word(s) to search field to retrieve sleep, sleeping, and other words using the same root. 
3. Click Widen and a new set is created containing the terms melatonin OR sleep in the record. The Search History box is updated with the new search results showing that 130 records now reside in Set 4. 
 

Exclude a Search 
The Exclude option eliminates records that contain the term you enter. For example, if you wanted to narrow your results to include records about melatonin, but not sleep, use the following steps: 

1. Highlight the first set you created with the search for melatonin. 
2. Enter sleep? in the Enter Word(s) to search field to retrieve sleep, sleeping, and other words using the same root. 
3. Click Exclude and a new set is created containing the terms melatonin but NOT sleep in the record. The Search History box is updated with the new search results showing that 19 records reside in Set 5. 
 

Combine Terms with Intersect 
The Intersect option is used to combine the terms from one or more highlighted sets with the AND operator. This is useful when you want to refine your search results to include the terms used in Set1 AND Set2 AND Set3, for however many sets you highlight. For example, the following Search History box shows three sets created by searches for fever?, cough?, and insomnia.  To combine the terms of Set 1 AND Set 2 (cough? AND fever?): 

1. Highlight Set 1 and Set 2 in the Search History box. 
2. Click Intersect. 

Combine Terms with Union 
The Union option is used to combine the terms from one or more highlighted sets with the OR operator. This is useful when you want to refine your search results to include the terms used in Set1 OR Set2 OR Set3, for however many sets you highlight. 

For example, to combine the terms of Set 4 (cough? and fever?) OR Set 3 (insomnia): 

1. Highlight Set 3 as well as Set 4 in the Search History box. 
2. Click Union. 

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Limits 
Limits are available for most databases to help target your search to the type of record you want. Common limits are for a specific language, such as English, or for records with abstracts. When limits are available, they are displayed after the search options in the form of check boxes. 

For example, the MEDLINE database has several limits for age groups and the types of records. To limit the records retrieved to Humans and English language for Set 1 containing the term melatonin: 

1. Highlight Set 1 in the Search History box. 
2. Click the check boxes Human and English, as shown below. 
3. Click Narrow. The Search History box updates with a new set of records.