Since evidence must ultimately be persuasive to an audience, arguers must adjust their usage of evidence for maximum appeal. The following tips are for framing evidence for maximum efficiency. Since argumentation is a social and communicative process, rhetorical technique enhances the persuasiveness of evidence.

Steps for using evidence:
1) Make a claim.
2) State your evidence.
3) Describe the evidence and show how it supports your claim.

The third step is critical for an effective argument. This is the difference between a weak use of evidence and a strong one. Telling your audience exatly what your evidence means and how it supports your claim increases the likelihood your audience will adopt your stance.

Types of evidence
Examples: used to clarify your ideas
Brief example: quick reference to illustrate a point

  • often used to introduce a topic

Extended example: long, descriptive example

  • Long detailed story. You want you audience to create a mental image of what you're talking about

Hypothetical example: imaginary situation

  • Used to relate a topic to your audience
  • Always follow up with more concrete, real-world evidence/statictics

Statistics: used to show frequency

  • Stick to simple forms (mean, median, mode)
  • Relate to audience to increase impact
  • Visual aids can be used to reinforce statistics
  • Use sparingly to increase impact and signify importance

Testimony quotations or paraphrases
Quotations: word for word

  • used when someone else conveys the meaning better than you could

Paraphrase: restating quotation in your own words

  • If qoutation is 3+ sentences, consider paraphrasing

Types of Testimony
Expert Testimony: information from expert in a certain field
Peer Testimony: information from people with firsthand experience

Criteria for Evaluating Evidence

The following criteria are often employed in evaluating evidence that supports arguments:

Recency. Is the support recent enough, or is it contradicted by more recent information?

Sufficiency. Is the support sufficient, or is it insufficient to make any conclusions?

Relevancy. Is the support directly relevant to the argument?

Clarity. Is the support clear and easy to understand, or is it marred by obfuscations?

Consistency. Is the support resonant with other evidence, or are there some discrepancies with individual or collective experience that make it unverifiable?

Qualification. Is the support qualified and reliable enough to assess the issue, or is it merely expressing an uninformed, untrustworthy opinion?

Bias. Is the support neutral, fair, reliable, and evenhanded, or is there some bias present?

Representative. Is the support representative of the information available, or are there substantial counterexamples that cast doubt upon the evidence?

Logic. Is the support well reasoned, or are there substantive holes in logic?

Tips for using evidence

Know your audience. Allows to to select more appropriate, relatable evidence. Cultural, gender, race, religion, and age differences of listeners can all greatly effect the impact of your evidence. Knowing your audience can allow you to adjust for these factors.

Be consistent with audience beliefs. Evidence is more likely to be accepted by an audience if it is consistent with an audiences’ beliefs. Of course, arguers often find themselves in situations where the audience beliefs are at odds with the evidence for their case—thus, they should attempt to undermine audience resistance to their evidence. Advancing a claim about the value of gun control for automatic weapons in a debate for the NRA will require work to have the audience accept evidence presented.

Maintain source appropriateness. Some sources are more compelling to particular audiences than others. In a debate about gender equality, arguers might be wise to avoid quoting from Playboy; in a debate about the existence of aliens, arguers might be wise to avoid quoting from the X-Files fan web site.

Acknowledge counterevidence. Smart arguers will acknowledge the presence of counterevidence and make comparisons with their own evidence or indictments of their co-arguer’s evidence. For example, an arguer might say “While there is some evidence that indicates otherwise, the evidence I have just presented is superior because…”

Rate evidence. Since all evidence was not created equal, make value judgments as the evidence is presented. For example, an arguer might say “The best study indicates that…”

Utilize sphere specific resources. Different spheres—public, private, and technical types of argument—require different norms for argumentation. Using highly technical terms for a lay audience would be ineffective; whereas using a technical terms for a group of physicists would be preferred.

Include details. Informing the audience of the details of a study, or methodology for research, enhances the suasory power of evidence. For example, an arguer might say “Utilizing both qualitative analyses of texts and quantitative analyses of survey data…”

Rely on experience. Argument’s search for common ground encourages utilizing agreed upon starting points for introducing evidence. For example, an arguer might say “From your experience as a decision-maker, you know that this type of evidence is most persuasive…”

Document evidence. Identifying the source for supporting material can enhance credibility, and allow the audience to follow up with their own additional research if desired. Well-documented sources enable audiences to conclude that there is substantial support for the speaker’s argument.

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