Misperception of Random Data

advertisement
Scientific Inquiry
SCI 105.020
The Psychology of Stupidity - I
Something Out of Nothing
Data, Information, and Knowledge
 Data
Also known as random data, raw data
Factual information (as measurements or statistics)
used as a basis for reasoning, discussion, or calculation
 Information
The communication or reception of knowledge or
intelligence
Presented as a message to another individual
 Knowledge
The fact or condition of knowing something with
familiarity gained through experience or association
Presented as concepts, predicates, rules, etc
Examples
 Let’s look at some data about a weather data set
concerning whether a game is played under
different weather conditions
The individual data entries, such as Outcast/Sunny,
Humidity/High don’t mean anything by themselves
We can generate informative reports using these data:
 Out of the 14 records, there are 6 with high humidity, 8
with normal humidity.
We can also discover some patterns
 We are 85.7% confident that it will play when humidity is
normal; 75% confident that it will play when humidity is
normal and it’s cold
Illusions
 Human cognitive mechanisms do have flaws
The Gateway Arch illusion (Gilovich, p17)
A similar optical illusion caused by two arches
 Which one is bigger?
The Muller Lyer illusion
More illusions can be found at
www.coolopticalillusions.com
 What’s more dangerous?
The illusions are so strong that
it is not eliminated simply by
knowing the correct answer
Illusions on Random Events
 Finding patterns out of our observations is the
right way to discover new knowledge
 But, be careful, overuse such strategies can also
cause problem
 Erroneous beliefs are hard to eliminate once
they are formed
 In this chapter, Gilovich emphasized on people’s
erroneous intuitions about how random events
should look
Nature Abhors a Vacuum
 People are disposed to see order, pattern, and
meaning in the world
Human nature abhors a lack of predictability and the
absence of meaning
As a consequence, we tends to see order where there is
none
 We simply tend to see something out of nothing
for no good reasons
Psychologists believe this is due to flaws in the cognitive
machinery we use to comprehend the world
Misconception of Random Data
 The dislike of randomness and seeking for order
and patterns may leads to
Cluster illusion
 The belief in a “hot hand” in basketball
The regression fallacy
 The representative heuristic is a major
contributor to these errors
Cluster Illusions
 Erroneous human intuition about random events
A random event shouldn’t have any clusters at all
Rather, it should be perfectly evenly distributed
 Coin-flipping exercise
First, make up a 20-flip sequence
Then, flip a coin 20 times
Compare
 C2 test:
 Can you reject the claim that the head-tail mix is evenly
distributed?
Representative Heuristic
 Read this paragraph and answer the question
Steve is very shy and withdrawn, invariably helpful, but
with little interest in people or the world of reality. He
has a need for order and a passion for detail.
Is Steve more likely to be salesperson or a librarian?
The Regression Fallacy
 The Sports Illustrated jinx
 Which is more effective: praise or punishment?
Download