Let’s Play the Facts

 By Eva Lin

“Are you 100% Sure?”

Fact About NTHU• The Ratio Between Male and Female Student is

6:4 in National Tsing Hua University.

=This means you have a high chance of end up surrounded by Male students. (66.666…%)

(This really depends in which Department)

Economics 1:1

中文系 1:10

外文系 2:13

工工系 1:1

動機系 4/100 = 4%!!!

“By smoking you are reducing 5 years of your

life”

FOR EVERY 100 AMERICAN

THERE ARE 80 GUNS

Is there Something Wrong?

• NTHU• Smokers• Guns

• An average salary is a common victim of this fact usages.

Outline• Where is Statistic Facts Used• Avoiding

o Critical Thinking o Common Knowledge

• Simple Biases • Different Averages• Numbers • Figures• Activity • Questions

Who Uses Statistic Facts?

• Newspapers • Magazines• Real Estate • Sellers

• Text Books• Family

• Friends• Everyone Does

“We live in a fact minded culture”

Avoiding

• Critical Thinking • Common Knowledge • Some Statistics Basis

Critical Thinking• Who says so – who is the one who is publishing

the result? Do they have anything to gain from the result

• How does he know – how did they measure this result? Was there any sampling bias?

• Did someone change the subject – Are the cause and effect getting muddled?

• Does it make sense?

Common Knowledge

• Geography • Economy • Algebra • Cultural Differences• History• …..

Sample Bias• A Bias within the Sample Space

(Tests) o Build In Bias• Honesty in Respondent • Pre-Selected Sample Space • Personal Pre-Perception• Unavailable Information with in a time

Which Magazine Do You Prefer to Read?

Another Way of Gathering Information

Averages• Different Type of Averages:

o Arithmetic average / mean: sum of quantities divided by number of quantities (Grading: GPA)

o Median: the middle point of the data which separates the data, the midpoint when data is sorted

o Mode: the data point that occurs the most in a given set of data

“The Average You Mention is Mean, Median or Mode?”

Don’t forget there is always a RANGE

Example of Average • Average pay of the employees is $1000, what

does this mean? This makes most of us think that almost everyone makes around $2000 – the reader thinks it is the median. But, the corporation can be talking about an arithmetic mean, where the boss might be earning say $10,500 and the rest of the 19 employees earn $500 each – the arithmetic average.

1 out of 30 3%

How you Number it.

• There 99% Chance you wont…• There is a 0.01 Chance… • There is a 1% Chance • 1 out 100 Student… • A Friend of your friend… (Getting Personal)

Figures VS Numbers “His Income Doubled”

ManipulationInfographics

MAKE YOUR FACTS

Hipoptasitis

• Arrived Asia: End of Summer • Deaths: 2,000 Adults & 400

Infants • Transmission 1 out of 40 • Side effect Risk 0.5%

HIP VACCINE SALES

You really really want to sell this because is

almost 200% of revenue!!

Peace Keepers

You believe this vaccine is unnecessary and actually

the rate of getting this epithetic is very low.

You believe that the risk of side effects is too high.

1-2

3-4

Review the Question

• Who says so – who is the one who is publishing the result? Do they have anything to gain from the result?

• How does he know – how did they measure this result? Was there any sampling bias?

• Did someone change the subject – Are the cause and effect getting muddled?

• Does it make sense?

Review

• Common Mistakes?• Average?• Questions to be asked?• Using Numbers and Figures

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