chapter 17: persuasive speeches

COM 114: Introduction to Speech CommunicationSpring 2007

Chapter 17: Persuasive Speeches


Content

• Defining Persuasive Speech

• Cornerstones of Persuasion

• Forms of Reasoning

• Toulmin Model

• Types of Credibility

• Organizing Persuasive Speech

• One-sided vs. Two-sided

Presentations

• Guidelines for Effective Persuasive

Speaking


Persuasive Speech

• Aims to change others by

prompting them to think, feel,

believe or act differently.


Characteristics of Persuasive Speech

1. Involves multiple communicators

2. Persuasion is not coercion or force

3. Persuasive impact usually is

gradual and incremental


Cornerstones of Persuasion

• Forms of proof or reasons people are

persuaded

1. Ethos - perceived personal character

of speaker; credibility

2. Pathos - emotional reasons for

attitudes, beliefs or action

3. Logos - rational or logical proof


Toulmin Model

• Toulmin explained that logical

reasoning consists of 3 components

1. Claims - assertions

2. Grounds - evidence/data that support

the claim

3. Warrant - explains the relevance of

the grounds to the claim; justification

of grounds


Toulmin Model

• Qualifier - word/phrase that limits the

scope of the claim

• Rebuttal - anticipates and addresses

reservations that listeners are likely

to have about claims


Credibility

• Speaker earns this by convincing

listeners that he/she has personal

integrity, is positively disposed

toward them, and can be trusted

1. Initial Credibility - before a

presentation begins

2. Derived Credibility - during the

speech

3. Terminal Credibility - end of

presentation


Organizing Speeches for Persuasive Impact

• Motivated Sequence Pattern

1. Listener’s attention is drawn to the subject

2. Establishes need by showing that a real

and serious problem exists

3. Speaker recommends a solution

4. Visualization - imagine the results

5. Speakers to the action step - appeal for

concrete action


One-sided and Two-sided Presentations

1. Listener’s expectations

2. Listener’s attitudes

3. Listener’s knowledge


Guidelines for Effective Persuasive Speeches

1. Create common ground with listeners

2. Adapt to listeners

3. Avoid fallacious reasoning



a) Ad Hominem Arguments - arguments

that go to the person instead of the

idea

b) Post Hoc, Ergopropter Hoc - “after

this, then this”

c) Bandwagon Appeal - argues that

because people believe/act in a

particular way, you should too



d) Slippery Slope - claims that once we

take the 1st step, more and more

steps inevitably will follow until some

unacceptable consequences results

e) Hasty Generalization - broad claim

based on too limited evidence

f) Red Herring Argument - speakers who

try to deflect listeners from relevant

issues



g) Either-Or Logic - implying that there

are only two options

h) Reliance on the Halo Effect - occurs

when we generalize a person’s

authority or expertise in a particular

area to other areas that are irrelevant

to the person’s experience and

knowledge

chapter 17: persuasive speeches

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