CSE1304 Lectures 3 & 4 - Critical Thinking

Lectures 3 & 4 - Critical Thinking

Analysing Information

Evidence

Use of Statistics

Graphs

Emotional Manipulation

Personal Attacks

Red Herrings

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Analysing information

Who said/wrote it?

What was their motive?

How did they come by their information?

What is their reputation?

Where do they work?

Who supports them?

Is the information complete?

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Consider the source

Primary?
- Direct from the origin
  - Scientist who conducted the research
  - Politician who made the statement
  - Judge who tried the case
  - Victim of the crime
- Someone who not only was there but was directly involved
  - Not just a witness
  - A participant
Secondary?
- Someone who talked to the primary source
- Someone who read the primary source
- Someone who was indirectly involved

And for both primary and secondary sources:

Is the statement complete?
Has it been taken out of context?
Have you been given the required background information to understand it?

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What supporting evidence is offered?

Statistics?
- Where did the statistics come from?
- Can they be trusted?
- Are relevant comparative statistics revealed?
  - 20% of smokers die of lung cancer
  - What percentage of non-smokers die of lung cancer?
  - "Universities receive more funding now than ever before" - David Kemp
  - Without comparative figures, statistics like these are inconclusive (but deceptively persuasive)
- Correlation
  - Is the relationship cause and effect
  - Are there other relevant factors?
    - Parents who have multiple car accidents are likely to have children who also have multiple car accidents...so?
- Surveys
  - Sample size
  - Derivation
  - Leading questions
    - "Product X is the greatest thing since sliced bread"
Appeal to authority
- Who is the "authority"?
  - Is he or she an authority on this topic?
  - What are the authority's motives?
  - What is the authority's reputation?
  - Can the authority be trusted?
Isolated examples
- "I have a friend who..."
- "I know a case where..."
Graphs

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Graphs - what questions should we ask?

Where is zero?
What's the scale?
What are the relative scales (for comparative graphs)
Is the change as large as it seems?
What is the rate of change?
How do the values depicted relate to the argument?
What other values would be relevant?

Example:

Temperature Graphs

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Emotional Manipulation

Appeals to emotion can be very effective
Especially:
- Guilt
  - "If you really cared about the environment, you'd buy this product."
  - "If you were a real friend you'd come to this nightclub with me."
- Greed
  - "If you invest in my company, you'll be rich."
  - "If you don't tell anyone we found this wallet, I'll split the contents with you."
- Parental instincts
  - "Your children are at risk, buying product X will make them safe."
  - "If you do that, you will scar your child (emotionally) for life."
- Status
  - "Everyone who's anyone will be there."
  - "This suit will make you look professional and impressive."
- Fear
  - "If we encourage immigration, foreigners will take all our jobs."
  - "Who don't you want to buy this home security system? Don't you want to safeguard your family?"

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Personal Attacks
(also known as 'ad hominem' attacks)

Attack the speaker, not the content
- Discredit the speaker
- Make the speaker look bad
- If the speaker is discredited, the speech is too.
- Take the focus off facts that can't be denied
- Put the focus onto people who are never perfect

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Red Herrings

Undeniable facts
Valid statements
BUT not relevant to the topic
- You want your children to be safe, don't you?
- You want to be able to protect yourself, don't you?
- You are concerned about the environment, aren't you?

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Lectures 3 & 4 - Critical Thinking

Analysing information

Consider the source

And for both primary and secondary sources:

What supporting evidence is offered?

Graphs - what questions should we ask?

Example:

Emotional Manipulation

Personal Attacks (also known as 'ad hominem' attacks)

Red Herrings

Personal Attacks
(also known as 'ad hominem' attacks)