Evidentiary Support

Learning Objective:

  • Identify evidentiary support in a persuasion essay.
  • Determine when a persuasion essay needs more or less evidentiary support.
  • Use a formal outline to identify missing evidence and analysis in a persuasion essay.

In a criminal trial, a defendant cannot be convicted unless the prosecution is able to provide enough relevant evidence to convince the jury that the suspect is guilty of whatever he or she is accused of doing. In the United States, the prosecution must prove its case "beyond reasonable doubt." If it does not, the defendant will likely walk away free. When writing a persuasion essayA writing that takes a position for or against something and tries to convince the reader to accept the same view. Also called an argument essay., your role is similar to that of the prosecutor's. You must provide adequate support to convince your readers that your argumentA set of statements or reasons making a case for or against something. has merit. At the same time, you should not fill your essayA short piece of writing that focuses on at least one main idea. Some essays are also focused on the author's unique point of view, making them personal or autobiographical, while others are focused on a particular literary, scientific, or political subject. with so much evidenceFacts, statistics, or expert testimony that supports a claim. that your own argument gets lost.

In this lesson, you will learn three techniques to help you evaluate whether you have provided the right amount of evidentiary supportEvidence that supports the claims or viewpoints expressed in an essay and helps convince readers that an argument has merit. Evidentiary support may take the form of facts and statistics, expert opinions, or anecdotal evidence. to persuade your reader of the validity of your claimA statement that something is true, such as the thesis of an essay. A successful writer must present evidence to prove his/her claim..

1. Create an outline from your rough draft.

OutliningA preliminary plan for a piece of a writing, often in the form of a list. It should include a topic, audience, purpose, thesis statement, and main and supporting points. is a tool that is usually utilized early in the writing process—before writing a first draft—to help organize ideas and formulate arguments. However, you can also use outlining further along in essay development—after writing a rough draftThe first version of a writing that will undergo rewriting, additions, and editing before it becomes the final draft.—to help identify holes in your thinking and gaps in your writing.

2. Identify the topic sentence, evidence, and analysis in each paragraph.

Identifying the topic sentenceA sentence that contains the controlling idea for an entire paragraph and is typically the first sentence of the paragraph., evidence, and analysisTo analyze is to make a thoughtful and detailed study of something. An analysis is the end result of analyzing. is a good way to evaluate the balance of evidence in your essay. One method for doing this is to assign each element a different color of highlighting. Then, using highlighting pens or the highlighting tools in your word processing program, color-code the elements. For example, use red for all topic sentences, yellow for all evidentiary support, and blue for all analysis. Once you've color-coded the entire essay, take a look at the distribution of the three colors. If a paragraph contains only one or two of the colors, you know you may need to add to your essay to balance it out. If you find a paragraph is mainly evidence, you will likely need to remove it, move it within the essay, and/or balance it out with more analysis. Ideally, you should have a good balance of evidence to support your topic sentence—using factsA piece of information that can be proven. Something that is true and indisputable., expertSomeone who is very knowledgeable about a topic. opinionPoint of view that shows a personal belief or bias and cannot be proven to be completely true., and anecdotesA brief, interesting story that writers often use to demonstrate a point within a work.—and your analysis should explain why your evidence is pertinent.


Opponents to organic farming argue that it is not as sustainable as its conventional counterpart; however, new research demonstrates that organic farming's benefits outweigh those of conventional farming. A 2011 study by the Rodale Institute reveals that organic farming produces higher yields than conventional agriculture; and contrary to popular belief, organic farming is also less expensive. Additionally, organic farming contributes to healthier soil and produces less greenhouse gasses.

As you can see from the color-coded paragraph above, the authorA person who wrote a text. clearly stated her main ideaThe most important or central thought of a reading selection. It also includes what the author wants the reader to understand about the topic he or she has chosen to write about., and then provided evidence that supported her claim; however, she did not analyze her data to show how the evidence supported her argument. She will need to go back and add analysis of the evidence to balance her essay.

3. Ask another person to read your essay and ask you questions about your argument.

If you have adequate and relevant evidence that supports the claims you make, the reader will likely not have very many questions; however, if the reader is confused about any of your points, be open to the idea that you have not adequately defended your position. Encourage your reader to take the opposing side to your argument. Try to defend your argument without referring to your essay. Have your reader note any arguments that you cannot defend or any points that you make that are not currently in your essay; these are the areas that you will need to focus on for your final draftThe last version of a writing that has been revised, edited, and proofread..

It is not possible or even desirable for all the arguments in a persuasion essay to carry exactly the same weight. But in general, balanced arguments make an essay more convincing. Points that have noticeably less support give the impression of weakness, and can cast doubt on the entire viewpoint. Arguments that have too much evidence can overwhelm and bore readers. The ideal argument has just enough evidence to be convincing and memorable with just one reading.