Deductive and Inductive Arguments

Deductive and Inductive Arguments

I can reason whether a statement is deductive or inductive- October 10, 2012

All bats are mammals. All mammals are warm-blooded. So, all bats are warm-blooded. All arguments are deductive or inductive. Deductive arguments are arguments in which the conclusion is arrived at logically because of premises (statements) believed to be true. Inductive arguments are arguments in which the conclusion is arrived at because of premises known are observed or experienced. Premise is a statement upon which an argument is based or from which a conclusion is drawn.

All bats are mammals. All mammals are warm-blooded. So, all bats are warm-blooded. Deductive. If the premises are true, the conclusion, logically, must also be true.

Joy is a law student. Most law students own laptops. So, probably Joy owns a laptop. In the example above, the word probably shows that the argument is inductive.

The rule says that no one who is not a member will be admitted. I am not a member. ? What is the conclusion and is it deductive or inductive?

The rule says that no one who is not a member will be admitted. I am not a member. ? What is the conclusion and is it DEDUCTIVE or inductive?

Deductive Reasoning Is based on proven facts and concludes with a proven fact. Conclusions have already been proven to be true.

Inductive Reasoning Is based on possible truths. The conclusions could be true, would probably be true, or likely could result based on the previous statements.

Every time I get in a fight my nose itches. I just noticed that my nose is itching. ? What is the conclusion and is it deductive or inductive?

Every time I get in a fight my nose itches. I just noticed that my nose is itching. ? What is the conclusion and it is deductive or inductive?

My last two Toyota’s have all performed well, so I am sure the next Toyota will perform well. Is this argument deductive or inductive? How can you tell?

McKenna says that Emma is outgoing and Emma is her friend. Emma said that McKenna is an honest person. So Emma is, most probably, outgoing. Deductive or Inductive?

McKenna says that Emmaa is outgoing and Emma is her friend. Emmaa said that McKenna is an honest person. So Emma is, most probably, outgoing. Deductive or Inductive?

So, What have you learned?True or False Conclusions based on deductive reasoning will always be true TRUE

So, What have you learned?True or False Conclusions based on inductive reasoning will always be true FALSE

So, What have you learned?True or False Conclusions based on inductive reasoning could be true…probably TRUE

The weatherman said that a low pressure front is moving into the area. The sky is overcast. I see people with umbrellas in the street. Therefore, it will rain. Is this argument deductive or inductive? How can you tell?

I come after Easton in the batting lineup. Easton just hit a homerun. It is my turn to bat. Deductive or inductive?

If any part of the statements, also known as premises, are false then the conclusions are false YES: It is called a false premise

Geese migrate south for the winterFlorida is always warmTherefore, Geese will probably migrate to Florida False Premise

There are no Viking’s jerseys allowed in Mrs. Young’s room. Sammy is wearing a Viking’s jersey. Mrs. Young is going to go off. Deductive or inductive? How can you tell?

Studying makes one highly intelligent. All 7th graders at SCMS study for long periods of time. So all SCMS 7th graders are highly intelligent. Inductive or deductive?

Graded Practice The following will be graded: Do you have any questions before we begin?

Inductive and Deductive Practice TCAP BOOK #’s 36. ____ 42. ____ True or False: ____ 3. Conclusions based on inductive reasoning will always be true. ____ 4. Deductive reasoning does not give new knowledge, but instead states what should already have been proven. ____ 5. If one of the premises is false, the conclusion will be false. Do the following use inductive or deductive reasoning (write “I” for inductive and “D” for deductive: ____ 6. All cats have fur. Xena is a cat. Therefore, Xena has fur. ____ 7. Some horses are big. All horses have tails. Therefore, anything with a tail is big. ____ 8. All humans have a nose. Bobby is human. Therefore, Bobby has a nose.

TCAP Book 36. __H___ 42. __F___ True or False: __F__ 3. Conclusions based on inductive reasoning will always be true. __T__ 4. Deductive reasoning does not give new knowledge, but instead states what should have already been proven. __T__ 5. If one of the premises is false, the conclusion will be false. Do the following use a false premise, inductive, or deductive reasoning (write “I” for inductive and “D” for deductive: __false premise__ 6. All cats have fur. Xena is a cat. Therefore, Xena has fur. __I__ 7. Some horses are big. All horses have tails. Therefore, anything with a tail is big. __D__ 8. All humans have a nose. Bobby is human. Therefore, Bobby has a nose. Listen for your %

Deductive and Inductive Arguments