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Write Clearly: Using Evidence Effectively

What is Evidence?

Most of the assignments you will do in university will ask you to make an argument, to take a stance, or to prove a hypothesis. The best way to do this is to research the topic, develop a thesis statement, hypothesis, or claim and then use evidence to support this claim.

Evidence is the facts, examples, or sources used to support a claim. In the sciences, this might be data retrieved from an experiment or a scientific journal article. In the humanities, it may be a quotation from the text, published information from academic critics, or a theory that supports your claims.

Think of evidence as the supports that buttress your claim, making it more solid than it would be alone. In fact, if you make a claim or an argument without evidence, your paper could appear to be unsupported opinion or not particularly well-researched. Even when the assignment elicits opinion, your paper will be more convincing if you provide evidence and the instructor may still be looking for an argument. It is also very important to remember that to use evidence effectively means to incorporate it well and to analyse it in a way that makes its connection to your argument clear and logical.

Evidence can be separated into two categories, primary and secondary sources.

What are Primary and Secondary Sources?

Evidence can be separated into two categories, primary and secondary sources.

Primary Sources

Primary sources are first-hand experiences, accounts, observations, reports, or narratives. Primary sources could include diaries, letters, contemporary newspapers, or eyewitness accounts of events. Official documents (e.g. the Canadian Charter of Rights and Freedoms), data collected from surveys, and lab results are also primary sources. In the humanities, the text you are writing about is also considered your primary text. So, for example, if you are writing a paper on Macbeth, then the play is your primary source. In the sciences, primary sources are also the results of an experiment that have been peer-reviewed and published in an academic journal.

Secondary Sources

Secondary sources are critiques written by academics and scholars. These sources are considered secondary because they examine primary sources to present an argument or support a point of view; as such, they may be selective with their evidence or insert themselves in a debate happening among a number of scholars. In the sciences, reviews, which are surveys of articles that demonstrate an understanding of a field, are considered secondary. It is a good idea to be aware of the bias in secondary sources when employing them as evidence.

Frequently the assignment will specify whether you need to use primary or secondary sources; however, if you are unsure about what kind of sources you need, ask your professor for clarification.

Among the forms of evidence you might draw from are:

  • Graphs, charts, tables, or figures
  • Statistics
  • Experiments or studies done by peer-reviewed sources
  • Surveys conducted by reputable sources
  • Interviews
  • Quotes or paraphrases from primary sources
  • Quotes or paraphrases from secondary sources

NOTE: In general, you should not use quotes in science papers.

How Do I Use Evidence?

Each discipline and each genre of writing will have standards against which it will gauge the academic merit and use of evidence. But some general rules apply (a detailed explanation of each rule follows this list):

  • Make sure your evidence is appropriate to the paper you are writing
  • Make sure the evidence does, in fact, support your argument or your claims
  • Tell your reader why this evidence supports your argument/claims
  • Make sure you have an appropriate amount of evidence
  • Make sure to appropriately cite your evidence

NOTE: Though not a general rule, your paper will be strengthened by acknowledging competing evidence – evidence that challenges your argument. This demonstrates that you have fully researched your topic and can counter claims against your argument.

Should I Cite my Evidence?

After integrating your evidence into your paper, it is very important that you properly cite your evidence. Each discipline has their preferred style (MLA, APA, Chicago, etc.); if you are unclear what citation style to use, ask your professor or teaching assistant for direction.

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