IV. Elaboration Likelihood Model Petty & Cacioppo What is the “Likelihood” that people will evaluate information in an “Elaborate” way? What increases the chance people will use critical thinking?
ELM – Two routes Central route Peripheral route
V. Logos Two types of Reasoning: Inductive Deductive
Inductive Reasoning Sherlock Holmes House, MD CSI
Deductive Reasoning Major Premise: Generally accepted idea minor premise: Specific example of this idea Conclusion: Proposition / claim MP, mp, C
Deductive Reasoning Major Premise: My niece likes pink (idea) minor premise: This doll is pink (example) Conclusion: She will like this doll MP or mp is often implied, not stated
Deductive Reasoning Major premise: (Worldview) American citizens have the right to free speech Minor premise: (Specific instance) Person A, a U.S. citizen, says controversial things Conclusion: Person A has this right
Deductive Reasoning Major premise: (Worldview) American citizens have the right to free speech Minor premise: (Specific instance) Person B, a U.S. citizen, says controversial things of a different sort Conclusion: Person B should be locked up (?)
Elements of Argument (Toulmin) Claim Support (Data) Warrant
Types of Argument You can argue from… Sign Example Analogy Causation
Arguing from sign Claim: It is going to rain Support: I observe dark clouds Warrant: Accepted idea that dark clouds are a sign of rain
Arguing from sign Example from UFO reading: Using political parties to draw conclusions about positions on an issue
Arguing from sign Tests Do signs generally indicate conclusion? Are there contradictory signs?
Arguing from Example Claim: It is going to rain Support: On three different dates in the past few months, similar weather patterns have produced rain Warrant: What is true in many cases will be true in this case
Arguing from Analogy Claim: School “A” should have XYZ policy Support: School “B” has success with XYZ policy Warrant: Since “A” and “B” are similar in many ways, they will also be similar here.
Arguing from Analogy Tests Are examples similar enough? “Apples and Oranges”
Arguing from Cause Claim: Home sales will increase Support: Mortgage interest rates have dropped Warrant: Lower interest rates are understood to lead to higher home sales
Arguing from Cause Tests Are events along sufficient to cause 2nd event? Are there other factors?
Fallacies Errors in reasoning Hasty generalization False cause (post hoc, ergo propter hoc) Either – Or (False dilemma) Straw man Ad hominem