generalization and example

8/6/2019 Generalization and Example

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Generalization andArgument by Example

forms of inductive

reasoning


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argument from generalization

Generalizations are one of the most commonforms of reasoning.

Definition: Generalizing involves attempts to

identify general patterns, gauge what is typical oraverage, or formulate general rules

Generalizing is necessary, indispensable Imagine what life would be like if you couldnt form

generalizations--if all knowledge was particularizedand fragmented.

Generalizing is also fraught with risks Think how many false stereotypes people hold about

race, gender, age, etc. What if Jim Abbot had believed people who said you

couldnt pitch in the major leagues with only one arm?

What if Stephen Hawking presumed that a person in awheelchair couldnt be a leading theoretical physicist?


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Bondes are dumb?

Blondes are dumb?

Does the stereotype refer only to

natural blondes?D

oes thestereotype only to female, notmale blondes?

Reese Witherspoon attendedStanford and won an oscar.

Hillary Clinton, law degree fromYale

Lisa Kudrow, degree in biologyfrom Vassar

Sharon Stone has a reported IQof 154

Kim Campbell, Canadas firstfemale prime minister, is blonde.


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White men cant jump?

Does the stereotype onlyapply to basketball?

Andrey Silnov, a Russian, won

the gold medal in the high jumpin Beijing in 2008.

Javier Sotomayor, a Cuban hasthe current world record in themens high jump.

Patrick Sjberg of Sweden hasthe 2nd highest world record inthe high jump

IgorPaklin, a Russian, has the3rd place world record,

Rudolph Povarnitsyn, anotherRussian, is 4th best. Andrey Silnov


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Asians are bad drivers?

AfricanorBlack

AngloorWhite

AsianandPacific

Islander

Hispanic orLatino

NativeAmerican

Percentage ofdeathsfromtraffic

fatalities

1.8 1.6 2.5 4.7 6.8

Does the stereotype apply to allAsians, or only some?

Are Taiwanese better than

Japanese or Vietnamese orKorean drivers? Does it apply to2nd or 3rd generation Asian-

Americans?

A study by the NHTSA publishedin 2006 revealed that Asiandrivers were not responsible for adisproportionate share of fatal

accidents As a percentage of the population

Hispanics and Native Americansaccounted for more fatal crashes.


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An Indian kid always wins thespelling bee?

An Indian kid (sub-Asian continent)always wins the national spelling bee?

4 of the past 9 winners were ofIndiandescent

National Spelling Bee Winners Since2000

2008 Sameer Mishra

2007 Evan ODorney

2006 Katharine Kerry Close 2005 Anurag Kashyap

2004 David Scott Pilarski Tidmarsh

2003 Sai R. Gunturi

2002 Pratyush Buddiga

2001 Sean Conley

2000 George Abraham Thampy


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Polling and surveys as a form ofgeneralizing

Public opinion polls

Nielsen ratings forTV shows

American Idol voting ratemyprofessor.com

call-screening on radio talk shows

To be truly valid a sample should be:

random

representative

sufficient in size.


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universal and statisticalgeneralizations

Universal generalization:Universal generalization: claims that all members of a group have certainattributes or characteristics

Asians are good at math.Feminists hate men.

Republicans favor tax cuts, Democrats oppose tax cuts.

Statistical generalization:Statistical generalization: claims that a percentage or a portion of a group hasa certain attribute or property.

76% of felons are recidivists

1 out of 3 children in the U.S. is born out of wedlock

19 of the 21 hijackers on Sept. 11 were Saudi Arabians. Contingent generalization: based on conditions or qualifications that must be

met for the generalization to hold true.Generalizations are more likely tohold true if they are confined to specific times, places, or situations

Most serial killers are male

The majority of journalists are Democrats


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inductive and deductivegeneralizations

Two types of generalizations: inductive and deductive

Inductive GeneralizationInductive Generalization:: bases a larger inference on an

example, sample, or particular instance

example: Babbs bought a Saturn and it runs well. Biff

bought a Saturn and it runs well. I guess Saturns are

reliable cars. (the generalization is based on a

nonrandom sample of 3 cars)

example: Of the 19 hijackers on Sept. 11, 15 wereSaudis. I think we can safely conclude that Saudi

Arabia is a breeding ground for terrorists.


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inductive and deductivegeneralizations

Deductive GeneralizationDeductive Generalization:: proceeds from a

general rule or general principle to a specific case

example: Brazilians love soccer. Hector is from

Brazil, so he probably loves soccer too.

example: Dont give money to that vagrant.

They are all winos and drug addicts.

example: Biff is a Republican, so of course hell

be opposed to gun control.


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tests of generalizations

How valid or reliable is the general rule?

Is the sample from which the generalization is

drawn random, and representative?

Is the sample from which the generalization is

drawn sufficient? (sample size)

Are there any exceptions to the rule?

Even if the general rule is true, does it apply in

this particular case?


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Reasoning by Example

A sub-set of inductive generalizations (a sample of one,

or a few)

Offers a generalization based on one or more cases to

other cases which are presumed to share the same

features as the example.

Examples may be based on personal experience,

hearsay, anecdotes, or case studies

example: testimonials on infomercials, The X47 Super mop

worked so well I threw away all my other mops!

example: deciding whether to take a class, see a movie, or

eat at a particular restaurant based on a friends say so.


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reasoning by example: Beware oftestimonials!

Thesetestimonials

serve as

examples of

how effective

diets,supplements, or

exercise

equipment is

He is a real person, but

was he selected at

random?


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Reasoning by example: Beware oftestimonials!

Before andAfter pictures

for miracle

diets, or

testimonials for

various productsare based on

examples.


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tests of examples

Is the example relevant or germane?

How typical or representative is the example?

Watch out for hand-picked examples

Do the examples cover a critical period of time?

Are there enough examples to prove the case?

Are there any negative or contradictory examples?

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