Once you start to narrow your topic, finding the right keywords is important. Don't be afraid to let your topic change as you do more research. Note: when the narrator says "one search" what she really means is "Article Quick Search"
If you cannot access the above video, you can watch it here
Here are some ways to narrow your topic:
Theoretical approach: Limit your topic to a particular approach to the issue. For example, if your topic concerns cloning, examine the theories surrounding of the high rate of failures in animal cloning.
Aspect or sub-area: Consider only one piece of the subject. For example, if your topic is human cloning, investigate government regulation of cloning.
Time: Limit the time span you examine. For example, on a topic in genetics, contrast public attitudes in the 1950's versus the 1990's.
Population group: Limit by age, sex, race, occupation, species or ethnic group. For example, on a topic in genetics, examine specific traits as they affect women over 40 years of age.
Geographical location: A geographic analysis can provide a useful means to examine an issue. For example, if your topic concerns cloning, investigate cloning practices in Europe or the Middle East.