??!??!

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 1

?Evaluating Causal Claims

?

學生思維訓練課程學生思維訓練課程學生思維訓練課程2© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

I hope the seat belt sign

is not turned on so

frequently! The plane

shakes so violently every

time it is turned on!

Is there a problem in the child’s reasoning?

學生思維訓練課程學生思維訓練課程學生思維訓練課程3© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 3

Is There a Relationship Between Ice Cream Sales And The Number of Shark Attacks?

Months

Ice CreamSales

0

100

00

200

00

Jan 　　　　　　　 Jul 　　　　　 Dec

Months

No. of Shark Attacks

0

4

8

Jan 　　　　　　　 Jul 　　　　　 Dec

學生思維訓練課程學生思維訓練課程學生思維訓練課程4© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

• What is the evidence?

• Is there a bias?

• Is the research approach appropriate?

Is There a Cause And Effect Relationship Between Youngsters Watching Violence Films And Their

Violent Behaviours?

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 5

Distinguish Between Fact, Opinion and Reasoned Argument

First of all, you should learn to distinguish: Fact Opinion Reasoned Argument

This is Because…

Evidence?

??! ??!6© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Good Thinking Requires Information and Reasons

Fact:

Tung Chee Hwa was the first Chief Executive of Hong Kong.

Opinion:

Mr Tung was a good Chief Executive.

Reasoned Argument:

Because of the differential appeals and concerns from different parties, groups and walks of life, the government should try its best to implement a policy that is favourable to all people.

學生思維訓練課程學生思維訓練課程學生思維訓練課程7© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

I hope the seat belt sign

is not turned on so

frequently! The plane

shakes so violently every

time it is turned on!

Is there a problem in the child’s reasoning?

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 8

What is Correlation?

Months

Ice CreamSales

0

100

00

200

00

Jan 　　　　　　　 Jul 　　　　　 Dec

Months

No. of Shark Attacks

0

4

8

Jan 　　　　　　　 Jul 　　　　　 Dec

??! ??!9© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

What is Correlation?

Is there a relationship between ice cream sales and the number of shark attacks? What kind of relationship is it?

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 10

What is Correlation?

Ice Cream Sales

No. of Shark Attacks

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 11

What is Correlation?

B rises when A rises. B falls when A rises.

Does correlation mean a cause and effect relationship?

PositiveCorrelation

NegativeCorrelation

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 12

Can You Identify the Type of Relationship?

Family Factors

Rebellious Teenager

Rebellious Teenager

Low Levels of Education

When A and B are

correlated

Low Levels of Education

Rebellious Teenager

Low Levels of Education

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 13

What is Correlation?

CorrelationCause and

Effect Relationship

??! ??!14© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Some Examples

Many private tutorial centres publicise the number of their students who got As or even straight As in public examinations.

學生思維訓練課程學生思維訓練課程學生思維訓練課程15© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

• What is the evidence?

• Is there a bias?

• Is the research approach appropriate?

Is There a Cause And Effect Relationship Between Youngsters Watching Violence Films And Their

Violent Behaviours?

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 16

Attractive Product Claims

Research Example:

Is laser fat reduction treatment effective?

Results in a week!

100% Safety Approved!

Proven Effectiveness!Money Back

Money Back

GuaranteeGuarantee

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 17

Attractive Product Claims

What questions would you ask to find out if the treatment is actually effective?

Hints:

Who will be the participants?Can everyone participate in the experiment?

How to choose the participants? Do all participants receive the same treatment?

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 18

Thinking about Result of Consumer Research

Random Sampling

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 19

Thinking about Result of Consumer Research

Laser Fat Reduction Treatment

No Laser Fat Reduction Treatment

Control Experiment

Experimental Group vs. Control Group

??! ??!20© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Thinking about Result of Consumer Research

Other Methods of Control•Placebo •Double Blind Study

• Significance of Result (that probably happened not by chance)

??! ??!21© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

How May Our Thinking Be Affected?

• What is Fallacy?- Errors in Reasoning and Logic

• Common Fallacies• Guilt by Association / Virtue by Association• Popularity & Testimonials• Weak Analogies• Appeals to Tradition

??! ??!22© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Guilt by Association andVirtue by Association

• Juvenile delinquent and reputation of school (Guilt by Association)

- If a student commits an offence, people will think that other students from the same school have bad behaviour too.

Can you think of other everyday examples of Guilt by Association and Virtue by Association?

•Favourable teacher and university (Virtue by Association)

- Your favourite teacher graduated from a certain university. Therefore, that particular university must be a good university.

??! ??!23© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Popularity & Testimonials

• Cosmetic products• Mobile phones

Can you think of other everyday examples of “Popularity & Testimonials”?

- Celebrity spokespersons and popularity terms such as “best-selling” or “most popular” are often introduced in the adverts of cosmetic products and mobile phones.

??! ??!24© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Weak Analogies

• Time spent on sports and study - Athletes train very hard for their successes. If they spend

the same amount of effort on their studies, they will get the same rewarding results.

Can you think of other everyday examples of Weak Analogies?

• A Man’s car and his girlfriend- We can infer the way a man treats his girlfriend from

the way he treats his car.

??! ??!25© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau

Appeals to Tradition• Husbands should work and wives should be

housewives - According to tradition, husbands are responsible for

earning money and wives are responsible for keeping the household.

Can you think of other everyday examples of Appeals to Tradition?

• School should finish early in summer - Schools used to end early in summer because of the hot

weather and the lack of air-conditioning in schools. Although most schools are now equipped with air-conditioning, we still feel that schools should end early in the summer.

??!??!

© EDB; D. Halpern, K. Ku, I. Ho, K.T. Hau 26

Evaluating Causal Claims…

Requires

- Effort

- Time

- and Critical

Thinking

Advantages

- Money-saving

- Wise Shopping

- Self-control