Using Evidence

Ask yourself the questions "Why do I believe my argument? Why should others believe it too?" The answers are the reasons you'll use to try to convince your readers that your argument is valid. Presenting these reasons and the evidence on which they are based (as well as explaining how they relate to your argument) are what constitutes the majority of an academic paper.

Evidence can come in many forms, which you can use as examples that support your argument:

  • Historical facts
  • Statistics
  • Textual evidence
  • Quotes from secondary sources
  • Real life experiences or anecdotes
  • Opinions of people in your field

It can be helpful to think of your argument as one main claim—the thesis—that is supported by several smaller claims, which are your reasons. For each reason, you present evidence—statistics, historical data, textual evidence, etc.—that supports that reason.

For instance, pretend your thesis argues that a politician is doing a poor job and should not be reelected. You could list reasons that she is untrustworthy: she slacks off at her job, she breaks campaign promises, and she has questionable ethics. You might use historical facts or statistics as examples of these traits: 60% of her past time in office was spent on vacation, she raised taxes after promising to cut them, and she was prosecuted for accepting illegal campaign contributions.

Regardless of its form, the evidence you provide should be from a reputable source, and it should be relevant to your paper. In other words, it should give your reader a reason to believe what your thesis asserts. Evidence doesn't do any good if it's off-topic.

Good places to start looking for evidence include:

  • Newspaper or journal articles
  • Books
  • The bibliographies of relevant articles and books
  • Government publications (e.g. CDC statistics)
  • Published scientific results
  • Websites or radio/television shows of experts on the topic

If you are having trouble finding suitable evidence, you might need to rethink your claim. Why did you believe it in the first place? Further investigate the source of your belief. If it is based on your life experience, you'll need to find examples of others who agree and perhaps think through a more rigorous reason behind your claim. You can always consult with your professor if you're having trouble.

To assess the quality of your evidence, ask someone familiar with your discipline, such as your professor or TA. You can also ask someone else to read over your paper. WAs in the Writing Center are always ready to do this for you; professors and classmates can also help you with specific advice based on course material. Here are several questions (adapted from William's and Colomb's The Craft of Argument) to help you think about the effectiveness of your evidence:

  • What are you claiming your reader should believe (i.e. what is your thesis)? Is your claim thought through carefully?
  • What reasons do you give your reader to believe your idea?
  • What evidence supports your reasons? Is the evidence based on reliable sources and facts?
  • What is the difference between your thesis and the evidence that supports it?

What is the connection between your evidence and your main point? Have you explained this connection clearly to your reader? Are you prepared to defend the connection to an unconvinced reader?