Skip to Main Content

Searching for Information


  • The key to being a savvy online searcher is to use common search techniques that you can apply to almost any database, including article databases, online catalogs and even commercial search engines.
  • This is important because searching library databases is a bit different from searching Google.
  • The techniques described on this page will enable you to quickly retrieve relevant information from the thousands of records in a database.
  • When you search a database and do not get the results you expect, ask for advice.  Library staff are happy to help you find what you need.

Boolean Operators

Boolean operators form the basis of mathematical sets and database logic.

  • They connect your search words together to either narrow or broaden your set of results.
  • The three basic boolean operators are: ANDOR, and NOT.

Why use Boolean operators?

  • To focus a search, particularly when your topic contains multiple search terms.
  • To connect various pieces of information to find exactly what you're looking for.
  • Example:   second creation (title) AND wilmut and campbell (author) AND 2000 (year)​

Use AND in a search to:

  • narrow your results
  • tell the database that ALL search terms must be present in the resulting records
  • example: cloning AND humans AND ethicsThe purple triangle in the middle of the Venn diagram to the right represents the result set for this search. It is a small set using AND, the combination of all three search words.

Be aware:  In many, but not all, databases, the AND is implied. 

  • For example, Google automatically puts an AND in between your search terms.
  • Though all your search terms are included in the results, they may not be connected together in the way you want.
  • For example, this search:  college students test anxiety  is translated to:  college AND students AND test AND anxiety. The words may appear individually throughout the resulting records.
  • You can search using phrases to make your results more specific.
  • For example:  "college students" AND "test anxiety". This way, the phrases show up in the results as you expect them to be.

Use OR in a search to:

  • connect two or more similar concepts (synonyms)
  • broaden your results, telling the database that ANY of your search terms can be present in the resulting records
  • example: cloning OR genetics OR reproduction.  All three circles to the right represent the result set for this search. It is a big set because any of those words are valid using the OR operator.

Use NOT in a search to:

  • exclude words from your search
  • narrow your search, telling the database to ignore concepts that may be implied by your search terms
  • example:  cloning NOT sheep

Search order:

Databases follow commands you type in and return results based on those commands. Be aware of the logical order in which words are connected when using Boolean operators: 

  • Databases usually recognize AND as the primary operator, and will connect concepts with AND together first.
  • If you use a combination of AND and OR operators in a search, enclose the words to be "ORed" together in parentheses.


  • ethics AND (cloning OR reproductive techniques)
  • (ethic* OR moral*) AND (bioengineering OR cloning)

Keyword vs. Subject Searching

If you don't know the title or author of an item, or if you are searching for literature on a topic, you will probably rely on keyword or subject searches. Successful searching often depends on understanding the difference.

Keyword Searches

Keyword searches are similar to Internet searches with Google in that the database will look for the words you use wherever they may be on a page. Regardless of whether the word is in a title, author name, place of publication or footnote, the page will be returned as a result.

Subject Searches

Subject searches, on the other hand, only return results in which the term being used appears in the subject field. Databases have different interfaces and use different terms, but most will provide these two options for searching

Keyword or Subject Search?

  • Do you know appropriate subjects?
    • Use a subject search unless you want to combine terms.
  • Do you want to combine terms?
    • Use a keyword search.
  • Is there little information about your topic?
    • Use a keyword search.
  • Does your subject search return 'no results'?
    • Use a keyword search

Keyword vs. Subject Search Infographic - details in text below the image


Keyword Searches

Subject Searches

Search for

Records that have the search term anywhere within them Records that have the search term in the subject headings part of that record


Depending on the terms you use, searches may retrieve no results or thousands. Searches with general terms often return many results Varies widely. Some searches will retrieve hundreds of results, but, if you choose a nonexistent term, you will get none


Varies. Results may be completely unrelated to your topic. For example, a search for "Philadelphia" returns records for every book published by the University of Pennsylvania Press regardless of whether the work is about Philadelphia High as long as you identify the correct subject for your topic


High: Terms can be combined in complex ways to design effective searches The flexibility of your search is limited by the manner in which subjects are structured in the database you are searching 


Truncation and Wildcards


Truncation, also called stemming, is a technique that broadens your search to include various word endings and spellings.

  • To use truncation, enter the root of a word and put the truncation symbol at the end.
  • The database will return results that include any word that starts with the letters in the root word, no matter how it ends.
  • Examples: 
    child* will find: child, childs, children, childrens, childhood
    genetic* will find:  genetic, genetics, genetically
  • Truncation symbols may vary by database; common symbols include: *, !, ?, or #


Similar to truncation, wildcards substitute a symbol for one letter of a word.

  • This is useful if a word is spelled in different ways, but still has the same meaning.
  • Examples: 
    wom!n will find both: woman and women
    colo?r will find both: color and (the British spelling) colour
Pilgrim Library:   
  Click the purple "Ask Us" side tab above