You don't want a topic that is too broad, that can lead to too much research to sift through and a paper that lacks focus. But you also don't want one that is too narrow, that can lead to not enough sources and a paper that almost impossible to argue.
Too broad: World War II
Too narrow: Survival rate of green-eyed Canadian soldiers during World War II battles on even days of the month.
Just right: How underground newspapers aided the French Resistance during World War II
Keywords translate your topic into search terms that you can use in the databases or online. You don't want to type in your entire topic sentence. Instead pull out the key terms. Also, don't forget about synonyms that could be used to describe your topic.
Topic Sentence: Climate change is affecting the survival rate of Emperor penguin chick born in the wild.
Keywords: climate change, global warming, penguins, Emperor penguins, survival, birth rate, chicks, eggs
Your keywords and your topic are not set in stone. You might find as you research that either of them may change based on what you find. It's all part of the research process!
Librarians love to organize information. One way we do this is by using subject headings. Since some subjects can be described using various terms (like cats or felines), librarians have come up with a standardized list, or controlled list, of subjects that can be used when describing resources. This list (known as the Library of Congress Subject Headings) provides the controlled vocabulary that every librarian uses when they describe the subject of a book, DVD, or any other object in the library's catalog.
The easiest way to understand subject headings is to see it in action. The most convenient example is the library's catalog. When you pull up the full record of a title, it will give you the subject heading for that item hyperlinked, so you can search for other titles with that descriptor.
You also will find subject headings in many of our online databases (like Academic Search Complete), where they help organize thousands of articles. They may not utilize the same list of subjects as the Library of Congress, you can still approach searching them the same way as in the library's catalog.
Start with a keyword search in a database or the library's catalog: find one or two items that match your topic and see what subject headings were used to describe them.
Start with a broad term (e.g. global warming) and browse through the related subject headings to see if there is one that matches your focus (e.g. Animals - effect of global warming on)
The same subject headings can be used
in more than one source: the ones you use in the catalog will likely work in a database too!