Research Tips: Database Search Tips

Boolean logic defines logical relationships between terms in a search. The Boolean search operators are and, or and not. You can use these operators to create a very broad or very narrow search.

• And combines search terms so that each search result contains all of the terms. For example, travel and Europe finds articles that contain both travel and Europe.
• Or combines search terms so that each search result contains at least one of the terms. For example, college or university finds results that contain either college or university.
• Not excludes terms so that each search result does not contain any of the terms that follow it. For example, television not cable finds results that contain television but not cable.

Note: When executing a search, And takes precedence over Or.

Source: EBSCO Discover Service

Too many results:

• Start small! Begin with just one or a few search terms. Add additional terms if you have too many results.
• Use good search terms - Use terms that are more specific. Do not use OR between terms that mean different things (for example, women OR salary).
• Too few search terms - If you only have one general term in the search box, consider another word that expresses what about that term you are interested in. 
• Use limiters - Limiters (such as date and format) give you more targeted results.
• Topic is too broad - Narrow the scope of your search. Think about the different aspects of your topic you will address and search for them separately. Then synthesize the information. You may need to narrow your topic if it is too large to cover in a short paper. 

Too few results:

• Use good search terms - Check spelling, and brainstorm synonyms or related terms. You can use OR between synonyms (for example salary OR pay OR compensation).
• Too many search terms - If you have three or more search terms, try removing one to see if your results improve.
• Too many limiters - Use only limiters that are absolutely necessary.
• Your topic is too narrow - What is the broader theme of your topic? Break your topic down and search for different parts separately. Then synthesize the information you find.

You can use wildcard and truncation symbols to create searches with unknown characters, multiple spellings or various endings.

• The asterisk (*) matches multiple characters.
• The hash sign (#) matches one optional character.
• The question mark (?) matches exactly one character.

1. Asterisk Wildcard

The asterisk (*) wildcard, also known as the truncation wildcard, is generally used to find word endings. Enter the root of a search term and replace the ending with the asterisk (*). For example, type comput* to find the words computer, computers, computing, computation.

The asterisk can be used within words to find multiple characters. For example, a search for hea*one will match words beginning with “hea” and ending with “one.” For example, headphone, headstone, hearthstone.

The asterisk (*) can be used between words to match any single word. For example, a search for midsummer * dream will match the phrases midsummer night’s dream and midsummer day’s dream.

2. Hash Wildcard

To use the # wildcard, enter your search terms and place # where an alternate spelling might contain an extra character. For example, type colo#r to find all records containing color or colour. Type p#ediatric to find all records with pediatric or paediatric.

3. Question-Mark Wildcard

To use the ? wildcard, enter your search terms and replace the unknown character with a ?. For example, type ne?t to find all records containing neat, nest or next.

Question marks at the end of words or character strings are not treated as wildcards. They are automatically removed from a query. For example, the question marks in the search terms below are ignored when searched:

To use a question mark as a wildcard at the end of a word, you need to put a # before the ? character. The hash before the trailing question mark indicates that the question mark should be treated as a wildcard to find exactly one character at the end a word. For example, a search for Monday#? will match Mondays but not Monday.

4. Combining Wildcards

Wildcards can be combined in a search term. For example, the following searches are allowed.

5. Restrictions When Using Wildcards

• Wildcards are not allowed as the first character in a search term.
• If there is only one leading character before a wildcard then, there must be at least one additional literal character within the first four characters.
  • f#r* (allowed because two literal characters are within the first four characters)
  • f??* (not allowed because only one leading character within the first four characters)
• When using any wildcard in a search term, the plural or possessive forms and any synonyms for the word will not automatically be searched. For example; when searching for colo#r, the plural words "colors" and "colours" are not searched.
• Wildcards do not work with Chinese (中文), Japanese (日本人), and Korean (한국어) languages.

Source: EBSCO Discover Service

In addition to keywords, subject headings (known as "Subject Terms" in EBSCO databases) can be helpful. Subject Terms are controlled terms--meaning a single term applies to a single concept, regardless of how many synonyms there are. Another way to think of them are as a standardized set of terms that bring consistency to the searching process. In EBSCO databases, you can add a SU delimiter by selecting the drop down menu in the advanced search feature (see screenshot below).