Evaluating Inductive Generalizations

1
Evaluating Inductive Generalizations
Chapter 11
In this tutorial you will learn how to critically
evaluate inductive generalizations.
2

• I know five or six truck drivers, and all of them
  are
• Democrats. So, probably most truck drivers are
• Democrats.

This argument is an inductive generalization. An
inductive generalization is an argument that uses
evidence about a limited number of things of a
certain type to make a claim about all or most
things of that type. In the example above, a
general conclusion about most truck drivers is
supported by personal experience of a relatively
small sample of only five or six truck drivers.
3
In evaluating inductive generalizations, there
are three questions we should ask Are the
premises true? Is the sample large enough? Is
the sample representative or typical of the
population as a whole? An inductive
generalization is a good one only if we can
answer "yes" to all three questions.
4
The last ten National League batting champs have
been women. So, probably all National League
batting champs have been women.
Based on your study of this chapter, is this a
good inductive generalization or not?
5
The last ten National League batting champs have
been women. So, probably all National League
batting champs have been women.
This is a bad inductive generalization. The
premise is false. Moreover, it is doubtful that
the sample size is large enough to support the
conclusion.
6
I've dated three men from Texas, and all of them
wore cowboy boots. So, it's probably the case
that all men from Texas wear cowboy boots.
Assuming that the premise of this argument is
true, is this a good inductive generalization or
not?
7
I've dated three men from Texas, and all of them
wore cowboy boots. So, it's probably the case
that all men from Texas wear cowboy boots.
This is a bad inductive generalization. The
sample size is much too small to justify the
conclusion.
8
Which sport is more popular in the U.S. moose
hunting or golf? In a recent survey of more than
1,000 residents of Fairbanks, Alaska, more than
65 said they preferred moose hunting. Therefore,
moose hunting probably is a more popular sport in
the U.S. than golf.
Assuming that the premise is true, is this a good
inductive generalization or not?
9
Which sport is more popular in the U.S. moose
hunting or golf? In a recent survey of more than
1,000 residents of Fairbanks, Alaska, more than
65 said they preferred moose hunting. Therefore,
moose hunting probably is a more popular sport in
the U.S. than golf.
This is a bad inductive generalization. Given
that the survey was limited to residents of
Fairbanks, Alaska, there is good reason to think
that the sample is not representative of
Americans as a whole.
X

• This is the end of the tutorial