Appropriate use of evidence will make or break your persuasive communications. 

The persuasive communicator has a responsibility to present accurate and timely evidence to support his or her arguments.  The ethical responsibility of the communicator to present evidence in an accurate manner is essential to quality argumentation.

• Persuasive communications can be divided into three main categories.
• Questions of fact: This argument deals with things that have already happened, are occurring now, or will happen in the future and reasons for such occurrences.
• Example:  Use of passive restraint devices will save thousands of lives over the next ten years.
• Questions of value:  This argument addresses the morality of an issue and calls for a judgment to be made: right/ wrong, good / bad, proper / improper.
• Example: The United States has a moral responsibility to protect human rights around the world.
• Question of policy: This argument advocates a plan of action to be taken and will include both fact and value in addition to a plan of action.
• Example: The United States will support with human resources and financial aid all United Nations sponsored human rights programs.

• Arguments should be supported by a variety of current and accurate evidence.
• Definition: Any term from the proposition which is elusive or obscure should be defined.  A terms may be defined by its denotation, the definition found in the dictionary, or connotation, the communicator's intent to use the word in a certain way or to give the word or phrase a particular range of focus of meaning.
• Factual Evidence: Facts are those things generally believed by the population to be true either through first hand observation or as reported by others. In theory, facts can be verified and are generally reported as: specific occurrences, statistics, exhibits, or presumptions.
• Specific occurrences: Examples or illustrations of events or conditions that show the fact to be true.
• Statistics: Numerical expressions reporting data in a factual manner.  Data may be reported in raw numbers, percentages, medians, etc.   It is the responsibility of the communicator to report statistics accurately and objectively.
• Exhibits: Includes visual or auditory evidence: recordings, pictures, artifacts
• Presumptions: Predictions based on uniform patterns of past experiences so probable as to be accepted without question. ( The sun will rise tomorrow.)
• Evidence based on opinion: Opinions are judged on interpretation of facts presented and evaluation of sources.
• Testimony: In offering expert testimony to support an argument, the communicator must link the testimony to the argument, show that the testimony is relevant, and reinforce the credibility of the source.

• The communicator has the responsibility to analyze all evidence and arguments for fallacies.
• Common logical fallacies and misuses of evidence include:

 

Loose Arguments	Hasty Generalizations
Circular Reasoning	Single Cause-effect
Slippery Slope	Non Sequitur
Either/Or	False Authority
Ad hominem	Bandwagon Thinking
Stacking the deck	Appeal to Emotion
Ignoring the question	Trivial objections

• Activities to reinforce the use of evidence and recognition of fallacies.
• Eye Spy a Product - Language Arts: This online activity reinforces identification of logical fallacies used in advertising
• Help students to recognize how advertisers frequently use logical fallacies to promote a product.  Give students a variety of magazines ot other reading materials which include advertisements.  Have students clip examples of ads that illustrate logical fallacies.  Have the students select one of the advertisements and re-write it using evidence which is accurate and ethical.  Follow with a discussion on truth in advertising and advertising ethics.
• Graphic Organizer for Pitfalls to Logical Thinking.  Ready to use tool to analyze types of appeals.
• Graphic Organizer for Evidence.  Handout to identify types of evidence