How many sources do I need?
An annotated bibliography is an excellent way to keep track of the research you gather for your project. Make no mistake about it— it is extremely important that you keep track of all of your evidence for your research project, and that you keep track of it from the beginning of the process of research writing.
There's nothing more frustrating than finding an excellent article or book chapter you are excited about incorporating into your research project, only to realize you have forgotten where you found the article or book chapter in the first place. This is extremely frustrating, and it's easily avoided by doing something like writing an annotated bibliography.
You could use other methods for keeping track of your research. For example, you could use note cards and write down the source information as a proper citation, then write down the information about the source that is important. If the material you know you want to use from a certain source is short enough, you might even write a direct quote, which is where you write down word for word what the source says exactly as it is written. At other times, you can write a paraphrase, which is where you write down what the source means using your own words.
Centralizes your research into one document that you can keep track of both as a print-out of a word-processed file and as a file you save electronically.
Allows you to "copy and paste" citation information into the works cited part of your research project.
Siegel, Marc. "Fighting the Drug (ad) Wars." The Nation 17 June 2002: 21.
Siegel, who is a doctor himself, writes about how drug advertising has undermined the communication between doctors and patients. He says that drug ads have driven up the costs of prescription drugs, particularly big selling drugs like those for cholesterol.
Wechsler, Jill. "Minority Docs See DTC Ads as Way to Address 'Race Gap.'" Pharmaceutical Executive May 2002: 32, 34. WilsonSelect Database. Eastern Michigan University Halle Library. 20 October 2002. <http://www.emich.edu/halle>.
This article is about a study that said that African-American doctors saw advertising of prescription drugs as a way of educating their patients. The ads are useful because they talk about diseases that affect African-Americans.
Even from the limited amount of information available in these entries, it's clear that a relationship between these articles exists. Both are similar articles about how the doctor/patient relationship is affected by drug advertising. But both are also different. The first article is from the newspaper The Nation, which is in many ways similar to an academic journal and which is also known for its liberal views. The second article is from a trade journal (also similar to academic journals in many ways) that obviously is an advocate for the pharmaceutical industry.
In other words, in the process of compiling an annotated bibliography, you are doing more than keeping track of your research. You are starting to make some comparisons and beginning to see some relationships between your evidence, a process that will become increasingly important as you gather more research and work your way through the different exercises that lead to the research project.
But remember: However you decide to keep track of your research as you progress through your project—annotated bibliography, note cards, or another method—the important thing is that you need to keep track of your research as you progress through your project!
Inevitably, students in research writing classes always ask how many sources they need to include in their research projects. In one sense, "how many sources do I need?" is a utilitarian question, one usually attached to a student's exploration of what it will take to get a particular grade. Considered more abstractly, this question is also an effort to explore the scope of a research project. Like a certain page or word count requirement, the question "how many sources do I need?" is an effort to get a handle on the scope of the research project assignment. In that sense, asking about the number of sources is probably a good idea, a little like asking how much something weighs before you attempt to pick it up.
But ultimately, there is no right or wrong answer to this question. Longer research projects tend to have evidence from more different sources than shorter projects, but there is no cut-and-dry formula where "X" number of pages will equal "X" number of sources.
However, an annotated bibliography should contain significantly more entries than you intend or expect to include in your research project. For example, if you think you will need or if your instructor requires you to have research from about seven different sources, you should probably have about 15 different entries on your annotated bibliography.
The reasons you need to find twice as many sources as you are likely to use is that you want to find and use the best research you can reasonably find, not the first pieces of research you can find. Usually, researchers have to look at a lot more information than they would ever include in a research writing project to begin making judgements about their research. And by far the worst thing you can do in your research is to stop right after you have found the number of sources required by the instructor for your project.