Write Clearly: Using Evidence Effectively

Much of how to use evidence is about finding a clear and logical relation between the evidence you use and your claim. For example, if you are asked to write a paper on the effects of pollution on watersheds, you would not use a story your grandfather told you about the river he used to swim in that is now polluted. You would look for peer-reviewed journal articles by experts on the subject.

Once you have found the appropriate type of evidence, it is important to select the evidence that supports your specific claim. For example, if you are writing a psychology paper on the role of emotions in decision-making, you would look for psychology journal articles that connect these two elements.

For example:

Emotions play a larger role in rational decision-making than most us think (claim). Subjects deciding to wear a seatbelt demonstrated an activity in the ventromedial frontal lobe, the part of the brain that governs emotion (Shibata 2001) (evidence). Or, if you are asked to write a paper on the gothic elements of Dr. Jekyll and Mr. Hyde, you might use as evidence a quote or two from the text itself.

For example:

The physical descriptions of the laboratory and the main house, in Dr Jekyll and Mr. Hyde, metaphorically point to the gothic elements in the novel (claim). The main house had "a great air of wealth and comfort" (13), while the laboratory door "which was equipped with neither bell nor knocker, was blistered and distained" (3) (evidence).

By referencing the study in the first example and supplying textual evidence in the second, the initial statement in the paragraph moves from opinion to supported argument; however, you must still analyze your evidence.

Once you have selected your evidence it is important to tell you reader why the evidence supports your claim. Evidence does not speak for itself: some readers may draw different conclusions from your evidence, or may not understand the relation between your evidence and your claim. It is up to you to walk your reader through the significance of the evidence to your claim and your larger argument. In short, you need a reason why the evidence supports the claim – you need to analyze the evidence.

Some questions you could consider are:

• Why is this evidence interesting or effective?
• What are the consequences or implications of this evidence?
• Why is this information important?
• How has it been important to my paper or to the field I am studying?
• How is this idea related to my thesis?
• This evidence points to a result of an experiment or study, can I explain why these results are important or what caused them?
• Can I give an example to illustrate this point?
• What are the strengths and weaknesses of the evidence presented?

If we look to our first examples, they may look like this once we add analysis to our evidence:

• Emotions play a larger role in rational decision-making than most us think (claim). Subjects deciding to wear a seatbelt demonstrated an activity in the ventromedial frontal lobe, the part of the brain that governs emotion (Shibata 2001) (evidence). This suggests that people making rational decisions, even when performing naturalized tasks such as putting on a seatbelt, rely on their emotions (analysis).

Or, when we look at the example of Dr. Jekyll and Mr. Hyde:

• The physical descriptions of the laboratory and the main house, in Dr Jekyll and Mr. Hyde, metaphorically point to the gothic elements in the novel (claim). The main house had "a great air of wealth and comfort" (13), while the laboratory door "which was equipped with neither bell nor knocker, was blistered and distained" (3) (evidence). The comforting and welcoming look of the main house is in sharp contrast to the door of the laboratory, which does not even have a bell to invite people in. The laboratory door is eerie and gothic highlighting the abnormal and mystical events that take place behind it (analysis).