Library Databases use keyword searching.  Do not search with sentences (natural language searching), such as, "How do I find research papers on the tree octopus."  Start with the most specific words or phrases, and then get broader.  In this example, you only need to put in the words "tree octopus"

You can start your search process by writing down a thesis sentence describing your topic,

1. Pick out the important words or phrases -- these are your keywords
2. Make a list of synonyms for each of the words or phrases
3. Search and see which are the best for your topic.
4. Put phrases in quotation marks:  for example "temperature change"

KEYWORDS or KEYWORD PHRASES are words or phrases that describe your topic.

Usually descriptive adjective and nouns.

When you do a keyword search in a library database, it searches minimally, the

• Title
• Subject or Descriptors  
• Abstract
• Author

Boolean Search

And / Or / Not

This is an algebraic concept, but don't let that scare you away. Boolean connectors are all about sets. There are three little words that are used as Boolean connectors:

• and
• or
• not

Think of each keyword as having a "set" of results that are connected with it. These sets can be combined to produce a different "set" of results. You can also exclude certain "sets" from your results by using a Boolean connector.

AND is a connector that requires both words to be present in each record in the results. Use AND to narrow your search.

The words 'whales' and 'dolphins' will both be present in each record.

OR is a connector that allows either word to be present in each record in the results. Use OR to expand your search.

Either "ebola" OR "Marburg" (or both) will be present in each record.

NOT is a connector that requires the first word be present in each record in the results, but only if the record does not contain the second word.

So a search for enteric bacteria that excludes salmonella would look like this