Unit 4: Fundamentals of Academic Essay Writing

24 Evidence Selection

Preview Questions:

  1. What types of evidence can you use in your essay?
  2. What are the criteria for determining if a piece of evidence is appropriate to use in your essay?
  3. Why should you strive to use a variety of types of evidence?

Your next step is to locate evidence to support your claims.

Criteria for selecting effective evidence

  1. You must able to understand and explain the evidence easily and clearly.
  2. The evidence should be directly related to your supporting points; it must support your thesis.
  3. A variety of types of evidence can make your writing more credible.

1 Easy to understand

If you find an article, but cannot understand the information in the article, it will be difficult or even impossible to use the evidence. You must therefore make sure you can understand the information you want use so you can paraphrase it clearly. Since most of the evidence you use will be paraphrased (not quoted), it is essential that you select information that you can easily express in your own words.

2 Supports your thesis statement

The evidence must be directly related to your topic and thesis statement. Even if the information is very interesting and easy to paraphrase, if it is not related to your thesis, it could lead to problems with logic or cause confusion in your writing.

3 Types of evidence

Using various types of evidence will show your reader you are familiar with the topic. There are two general categories of evidence, documented and undocumented.


Documented evidence is information for which the writer provides a source (and includes a citation). Documented evidence has therefore, been “documented” or “written down” previously and recorded for the public.

Types of documented evidence may include facts, statistics, expert opinions, examples, or anecdotes that the reader can locate in the original publication based on the citation and reference.


  • Nearly 98% of UW students bring a laptop or other device to class (Pierce, 2013, p. 1).
  • The UW-Madison will offer free tuition to transfer students who are the first in their families to attend college (Savidge, 2017, p. 1).
  • Note: If you are writing an essay about social media use among college students, it would be fairly easy to look at the percent (the number of) students who have Facebook or Instagram accounts. You could include these numbers, along with a citation and reference, in your essay as documented evidence.


Undocumented evidence may include general knowledge that most people accept to be true. What constitutes such shared knowledge may differ depending on the audience, but a good way to think about this is to ask yourself whether or not it is likely that most people will know what you are writing about without having to look up the information.


  • Teenagers feel pressure to fit in with those around them.
  • In the United States, cars drive on the right side of the road.
  • Note: It is also possible that some facts can be undocumented.
    • It is a simple fact that the earth travels around the sun; we all know and accept this as a truth, and it’s unnecessary to include a citation.
    • Now imagine you are writing an essay about college students and social media. It may be common knowledge that having a social media account is typical for most college students. Therefore, it may be possible in your essay to assert that most college students have some type of social media account, and this assertion could be considered undocumented evidence, which means you would not need to include a citation.
      • However, such an assertion could further be supplemented (and strengthened) with documented evidence such as which particular accounts are most common and what percent of students have them. In this way, documented and undocumented evidence can work together.
  • Another rough guideline is that if you can easily locate the information in five sources, it might be considered undocumented. Check with your instructor if you are unsure whether evidence is undocumented.

4 Types of evidence: Support your writing with a variety of evidence

Look at the types of evidence below and their examples. Which are most appropriate for academic writing?

type example
1.     fact A study conducted last year shows a link between eating animal products and an increase in lifestyle diseases, such as type two diabetes.
2.     statistic Ninety-eight percent of all UW students bring a portable device, such as a PC or tablet, to class.
3.     expert opinion Linguist Steven Pinker believes people who are bilingual experience culture differently than monolingual speakers.
4.     example Many online and technical companies are allowing their employees to telecommute, or work from home. Apple’s customer service employees, for example, can work remotely.
5.     personal experience I prepared for my chemistry test by meeting with a study group every week, and it really helped me a lot. My weekly quiz scores improved.
6.     undocumented evidence Most first year students live in the dorms and then move off campus when they are sophomores or juniors.

Key Takeaways

  • Strive to use documented evidence in your essay.
  • If you are unsure whether evidence is documented or undocumented, ask your instructor.
  • Use a variety of types of evidence and perspectives to make your essay more credible.

Knowledge Check: Revisit this exercise on Common Knowledge


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