You will be working with your elbow partner…decide right now who will be Partner A and who will be Partner B

Key Terms Argument: a conclusion together with

the premises that support it Premise: a reason offered as support

for another claim Conclusion: the claim being supported

by a premise or premises Valid: an argument whose premises

genuinely support its conclusion – If all the premises are true, it is impossible for the conclusion to be false.

Reasoning!? What’s that??? Reasoning is the act of drawing a conclusion.

You use premises to help you draw a conclusion. Some conclusions are more reliable than others.

It’s important to know if a conclusion was made using deductive reasoning or inductive reasoning. One is based on KNOWN FACTS that can be proven. The other is based on OBSERVATIONS that don’t always mean what you think they do! Why is important to know which one was used??

How do we start??

Reasoning starts by examining a premise, or a statement.

After examining the premise, a conclusion is made.

Deductive Reasoning Deductive reasoning is the process of

reasoning from known facts to conclusions. The known facts are trusted, or sound, premises.

When you reason deductively, you can say “therefore” with certainty.

If your facts are true to begin with, then your conclusions will also be true.

Deductive Reasoning Example Known Fact: The brochure for soccer camp

says cut-off date for camp registration is June 6. All kids registering after that date will go on a wait list, no exceptions.

Known Fact: It is three days past the cut-off date, and you have not registered your child.

Conclusion: Your child will not be registered and will go on the wait list.

Is the conclusion definitely true? Partner A, tell partner B what you think the

answer is and why. YES! The argument starts with KNOWN FACTS! The conclusion is based on FACTS! If the cut off date is June 6 for registration,

and you are trying to register after June 6, then you go on a waiting list! No exceptions!

The conclusion can be made with certainty. It is firm!

Will more evidence make your argument stronger? If you saw a website or got a phone call that

also said the deadline was June 6, would this make your conclusion more convincing?

Partner B, tell Partner A what you think the answer is and why.

NO!

In deductive reasoning, once a solid statement is made, you do not need more statements to improve your conclusion.

Deductive Reasoning

Does the argument start with a known fact or an observation?

Is the conclusion definitely true?

Can you add more evidence to make it more convincing?

Inductive Reasoning Inductive reasoning is the process of going

from observations to conclusions. The premise is something you have observed.

This type of conclusion is sometimes called

an inference.

Successful inductive reasoning depends on the quality of your observations, or evidence.

Inductive Reasoning Example Observation: Susan is seen walking from

her car to her home with a brand new tennis racket.

Observation: Susan’s son, David, loves tennis, and today is his birthday.

Conclusion (inference): Susan has bought the tennis racket for David.

Is the conclusion definitely true? Partner B, tell Partner A what you think the

answer is and why.

NO!

Susan could have borrowed a tennis racket from someone.

Susan could have bought herself a tennis racket.

The conclusion could be described as probable, but not firm.

Will more evidence make your argument stronger?

If you found a receipt for a tennis racket in Susan’s car and a birthday card with a picture of a tennis player on the front, would this make your conclusion more convincing?

Partner A, tell partner B what you think the answer is and why.

YES! In inductive reasoning, more evidence makes

your argument more convincing.

Inductive Reasoning

Does the argument start with a known fact or an observation?

Is the conclusion definitely true?

Can you add more evidence to make it more convincing?

Let’s take a moment to review…

What have we learned so far today?Reasoning is used to draw conclusions.There are two types, deductive and inductive.Deductive reasoning begins with known facts, the

conclusion is firm, and additional evidence does not help make the conclusion more convincing.

Inductive reasoning begins with observations, the conclusion could be different than what we think, and more evidence would help make the conclusion more convincing.

Model – Deductive or Inductive The National Heart Institute

researchers state that if you fry food, you will add more fat than if you had baked the food. The choices in the cafeteria today are fried chicken and baked chicken. The fried chicken has more fat in it than the baked chicken.

Model Known fact: The National Heart Institute

researchers state that if you fry food, you will add more fat than if you had baked the food.

Known fact: The choices in the cafeteria today are fried chicken and baked chicken.

Conclusion: The fried chicken has more fat in it than the baked chicken.

More evidence? Don’t need it! The researchers are trusted experts. It’s a FACT, fried food has more fat than baked food!

A different conclusion? No! There’s no way you can be wrong if the known fact is correct!

Is this deductive or inductive reasoning?Questions to ask yourself:

Does the argument start with a known fact or an observation?

Can you add more evidence to make it more convincing?

Is there any other conclusion you could make?

Whole Group – Deductive or Inductive?

Your teacher was sneezing and blowing her nose a lot today. You did not see your teacher after lunchtime today, and you noticed a substitute teacher in her classroom. Your teacher left early to go to the doctor.

Whole Group – Deductive or Inductive?

Observation: Your teacher was sneezing and blowing her nose a lot today.

Observation: You did not see your teacher after lunchtime today.

Conclusion: She left early and went to the doctor. More evidence? This would help confirm, or verify,

our conclusion! If we overheard her telling a coworker that she was going to the doctor, our conclusion would be more convincing!

A different conclusion? Of course! Our teacher could be going to a meeting. That doesn’t mean she isn’t sick, but we can’t say FOR SURE that she is going to the doctor.

Partner – Deductive or Inductive? You will be responsible for deciding whether

or not an example uses deductive or inductive reasoning.

You must explain your decision to your partner.

How will you decide which type of reasoning was used to draw the conclusion?

Partner – Deductive or Inductive? Partner A – Your best friend looked upset in

the hallway today. Lots of students were holding Social Studies tests in their hands. Your friend got a low score on the test.

Partner B – Students who receive more than 2 tickets are not allowed to go to incentive. John has received 4 tickets this grading period. He will not be at the incentive.

Partner B! Tell us what Partner A decided! Your best friend looked upset in the hallway

today. Lots of students were holding Social Studies tests in their hands. Your friend got a low score on the test.

Known facts or observations? Observations Is the conclusion definitely true? NO! Would more evidence make the conclusion

more convincing? YES! What type of reasoning is this? INDUCTIVE!

Partner A! Tell us what Partner B decided! Students who receive more than 2 tickets are

not allowed to go to incentive. John has received 4 tickets this grading period. He will not be at the incentive.

Known facts or observations? Known facts! Is the conclusion definitely true? YES! Would more evidence make the conclusion

more convincing? NO! What type of reasoning is this? DEDUCTIVE!

Two Traditional Means of Approaching the Thesis

1. deductive reasoning the thesis appears toward the beginning of

the text, then specific details follow in the body of the essay that support this point

2. inductive reasoning the reader/writer first develops the

importance of the point s/he wishes to make, THEN synthesize multiple points to infer a GENERAL thesis

Deduction Versus InductionDeduction Versus Induction

Deductive reasoning is either “valid” or “invalid.”

An argument is VALID if it has the following hypothetical or conditional property:

IF all the premises are true, then the conclusion CANNOT be false.

Inductive reasoning enjoys a wide range of probability; it can be plausible, possible, reasonable, credible, etc.

the inferences drawn may be placed on a continuum ranging from cogent at one end to fallacious at the other.

Instead of Valid or Invalid, think of these arguments as strong or weak.

Deduction Versus InductionDeduction Versus Induction--still more--still more

Deductive reasoning is commonly found in the natural sciences or “hard” sciences, less so in everyday arguments

Occasionally, everyday arguments do involve deductive reasoning: Example: “Two or

more persons are required to drive in the diamond lane. You don’t have two or more persons. Therefore you may not drive in the diamond lane”

Inductive reasoning is found in the courtroom, the boardroom, the classroom, and throughout the media

Most, but not all everyday arguments are based on induction◦ Examples: The

“reasonable person” standard in civil law, and the “beyond a reasonable doubt” standard in criminal law

Deduction—Induction Deduction—Induction and high school assessmentsand high school assessments

The majority of the essays you write in high school are developed using deductive reasoning.

Classes that require this style of reasoning in their essays are:AP World HistoryAPUSH11th and 12th grade

history coursesSome aspect of

science courses

OTHER FACTS:AP Lang and AP

Lit require much more variety in essay approach.

Much of the nonfiction reading you do in your LitComp classes will be inductively written.

Let’s Practice!

Start at your assigned number with your table group.

Answer the following questions for each number:Is this example Inductive or Deductive?Why do you think this?Is the reasoning Valid or Invalid?Why do you think this?