Inductive Inductive ArgumentArgument

Identifying and Identifying and Evaluating Inductive Evaluating Inductive ArgumentsArguments

GeneralizationsGeneralizations Inductive argument Inductive argument

move from things known move from things known to things unknown.to things unknown.

Sample- item or items we Sample- item or items we know something about.know something about.

Target class- group of Target class- group of items to which we wish to items to which we wish to extend our knowledge.extend our knowledge.

Types of GeneralizationsTypes of Generalizations

UniversalUniversal- moves - moves from sample to draw from sample to draw conclusion about conclusion about totaltotal target class. target class.

All All crows are black.crows are black. NoNo whales are fish. whales are fish.

Statistical GeneralizationStatistical Generalization

Draws a conclusion about Draws a conclusion about a a portion of portion of the target the target group.group.

1/5 of adult Americans are 1/5 of adult Americans are obese.obese.

MoreMore teenagers die of accidents teenagers die of accidents related to alcohol than do adults.related to alcohol than do adults.

Most Most jungles are hot.jungles are hot.

Analogical Analogical GeneralizationGeneralization

Draws a conclusion about Draws a conclusion about a target item on the basis a target item on the basis of a shared similarity or of a shared similarity or similarities.similarities.

This pair of shoes, like these This pair of shoes, like these shoes, is made of leather, has shoes, is made of leather, has the same style and same maker. the same style and same maker. Thus, like these shoes, this new Thus, like these shoes, this new pair of shoes will be comfortable.pair of shoes will be comfortable.

Causal GeneralizationCausal Generalization

Draws a conclusion Draws a conclusion about an observed about an observed relationship, i.e., that relationship, i.e., that this relationship will this relationship will always occur, on the always occur, on the basis of previously basis of previously observed instances of observed instances of the relationship.the relationship.

ExampleExample at time 1, y follows x.at time 1, y follows x. at time 2, y follows x.at time 2, y follows x. at time 3, y follows x.at time 3, y follows x. etc.etc. Thus, x Thus, x causes causes y.y.

Functional Functional CausationCausation

Draws a conclusion about Draws a conclusion about a relationship, i.e., that it a relationship, i.e., that it is causal on the basis of a is causal on the basis of a correlation.correlation. time 1time 1 y increase as x does.y increase as x does. time 2time 2 y increase as x does.y increase as x does. time 3 y increases as x does.time 3 y increases as x does. Thus x & y causally related, one is Thus x & y causally related, one is

the function of the other.the function of the other.

Evaluation Evaluation CriteriaCriteriaClear definition-class Clear definition-class & characteristics.& characteristics.

“ “Former mental Former mental patients are more patients are more law-abiding than law-abiding than other citizens.”other citizens.”

Evaluation Criteria

Similarity of sample Similarity of sample and target?and target? People surveyed by People surveyed by phone from 9a.m.-phone from 9a.m.-3p.m. 3p.m.

Target- AmericansTarget- Americans

Representative Representative SampleSample Is the sample typical of the Is the sample typical of the

class under a wide variety of class under a wide variety of circumstances?circumstances?““All fiddle crabs enter their All fiddle crabs enter their

burrows and close them when burrows and close them when the tide flows in.the tide flows in.

13 different species13 different species East Coast, West Coast, East Coast, West Coast,

Manila Bay, Italian Coast, etc.Manila Bay, Italian Coast, etc.

Evaluation Evaluation CriteriaCriteria Sufficiency of sample Sufficiency of sample

size. size. –varies according to –varies according to material being studied.material being studied.

All members of this class are All members of this class are brilliant, thus all CSUB students brilliant, thus all CSUB students areare brilliant.brilliant.

This water boils at 120 degrees This water boils at 120 degrees Fahrenheit. Thus water boils at 120 Fahrenheit. Thus water boils at 120 degrees Fahrenheit.degrees Fahrenheit.

Evaluation CriteriaEvaluation Criteria Scope- how cautious is the Scope- how cautious is the

conclusion in terms of conclusion in terms of sample?sample?

All East Coast Fiddler crabs; All East Coast Fiddler crabs; all American Fiddlers; All.all American Fiddlers; All.

The Roadrunners have won The Roadrunners have won all their games so far; thus all their games so far; thus they will have an undefeated they will have an undefeated season.season.

AnalogyAnalogy I am going to take Psychology I am going to take Psychology

310 next quarter because it is 310 next quarter because it is taught by Professor Good and taught by Professor Good and should be interesting. I took should be interesting. I took Psychology 110 and 200 with him Psychology 110 and 200 with him and they were interesting.and they were interesting.

Is it important that Psychology Is it important that Psychology 310 deals with rat behavior and 310 deals with rat behavior and studies while the other courses studies while the other courses dealt with human psychology?dealt with human psychology?