Truncation is also known as wildcard searching. It lets you search for a term and variant spellings of that term.
To truncate a search term, do a keyword search in a database, but remove the ending of the word and add an asterisk (*) to the end of the word. The database will retrieve results that include every word that begins with the letters you entered.
For more precise searching, connect your keywords in a meaningful way using the words AND, OR, and NOT.
Think of these connecting words as a bridge between keywords or concepts which allows you to narrow or broaden your search.
The more keywords you connect with AND, the fewer results you will retrieve. The database will need to find each of your keywords in the text in order to show it to you.
For example: "homeless youth" and education and "new york city"
Be careful not to add unnecessary words to AND searches. You might miss pertinent information. Sometimes the simpler the search, the better.
Here we are less picky with what terms we want to retrieve. Using OR is also helpful when we are searching for a concept that is described equally well by more than one term.
For example: cars OR automobiles
environment AND (water OR lake* OR river* OR stream*)
Here the first search is asking for all information pertaining to cars or automobiles.
The second search is a little more detailed, but more precise.
This type of search is good to use when you already know what you DO NOT want. Let's say you are doing a search on new cars but you are only interested in American made models.
For example: (cars OR automobiles) NOT Europe.
When you find an article or book that is useful for your research, you probably know to consult its bibliography or reference list to find other potentially relevant sources. In this way, you're tracing the scholarly conversation backwards in time. But you can also trace citations forward to find newer scholarship that cites the source you have in hand.
You can also search within the results to find only sources that mention a particular work or other keyword.
You can also try Google Scholar's "Related articles" link, which uses Google's proprietary algorithms to pull up similar articles.