1. ARGUMENTS: Deduction and Induction
BBI 3420 / 3436
ARGUMENTS: Deduction and Induction

2. Overview Examining deductive and inductive arguments.
Telling the difference between the two.
Different kinds of each argument form.
Types of fallacies

3. Types of arguments Deductive arguments Inductive arguments
An argument in which it is impossible for a conclusion to be false if its premises are true.
Inductive arguments
An argument in which it is improbable for the conclusion to be false if its premises are true.

4. Deductive Reasoning
Starts with a general rule (a premise) which we know to be true. Then, from that rule, we make a true conclusion about something specific.

5. Deductive Reasoning
The process of reasoning from known facts to conclusions. When you reason deductively, you can say “therefore” with certainty. If your facts were firm to begin with, then your conclusions will also be firm.
The conclusion claims to follow necessarily from the premises.
Example:
Socrates is a man.
All men are mortal.
Therefore, Socrates is mortal.

6. A deductive argument
is one in which it is impossible for the premises to be true but the conclusion false.
It is supposed to be a definitive proof of the truth of the claim (conclusion).
Premise  All men are mortal.
Premise  Socrates was a man.
Conclusion  Socrates was mortal.
If the premises are true (and they are), then it simply isn't possible for the conclusion to be false.
If you have a deductive argument and you accept the truth of the premises, then you must also accept the truth of the conclusion.

7. Deductive Reasoning Is…
Deductive reasoning is when you start from things you assume to be true, and draw conclusions that must be true if your assumptions are true.
For Example
All dogs have a tail.
Benji is a dog.
Therefore Benji has a tail.

8. A deductive argument
True
Premise
Conclusion

9. Deductive Reasoning Example:
Smith owns only blue pants and brown pants. Smith is wearing a pair of pants today. So, Smith is wearing either blue or brown pants today.

10. Say this
Not this
Gravity makes things fall. The apple that hit my head was due to gravity.
The apple hit my head. Gravity works!
They are all like that -- just look at him!
Look at him. They are all like that.
Toyota make wonderful cars. Let me show you this one.
These cars are all wonderful. They are made by Toyota, it seems.
There is a law against smoking. Stop it now.
Stop smoking, please.

11. Who is known for using Deductive Reasoning?

12. Sherlock Holmes
Sherlock Holmes would use deductive reasoning to help solve crimes.
Example:
Sherlock Holmes could help solve a mystery by making inferences. If Holmes saw a pack of cigarettes by a victim (the victim did not smoke), Holmes can make the assumption that the killer is a smoker.
Andrew Ault

13. However…
Deductive reasoning may not be the most accurate way of solving a problem, cause we all know that assumptions can be wrong.

14. Other faults of deductive reasoning
All Graduates of M.I.T. are Engineers
George is not from M.I.T.
Therefore George is not an Engineer
Everybody from Texas is a cowboy
Scott is from Texas
Scott is a cowboy

15. What professions do you think commonly use Deductive Reasoning?

16. Doctors
Journalists
And many more...
Lawyers
Detectives

17. Why?
These professions tend to ask a lot of questions to try to solve problems or to prove a point.
Often they would have to make assumptions to solve problems.
They would use rules and widely accepted beliefs to prove their argument.
An attorney states that his client is innocent because the crime victim was hit by a car. Since his client does not have a license. He can deduce that his client is innocent.

18. Deductive Reasoning

19. Deductive Reasoning
From vague
To specific

20. Inductive Argument
The process of going from observations to conclusions.
This type of conclusion is sometimes called an inference.
Conclusion claims to follow probably from the premises.
Example:
Socrates was Greek.
Most Greeks ate fish.
Therefore, Socrates probably ate fish.

21. Inductive Reasoning
Observing that something is true many times, then concluding that it will be true in all instances
Using the data to make a prediction

22. Inductive Reasoning

23. Inductive Reasoning
From specific
To vague

24. An inductive argument
is one in which the premises are supposed to support the conclusion.
If the premises are true, it is unlikely that the conclusion is false.
The conclusion probably follows from the premises.
Premise  Socrates was Greek.
Premise  Most Greeks eat fish.
Conclusion  Socrates ate fish.
Even if both premises are true, it is still possible for the conclusion to be false (maybe Socrates was allergic to fish).
Words which tend to mark an argument as inductive include probably, likely, possibly and reasonably.

25. A inductive argument True Premise True Premise True Probably
Conclusion

26. Inductive Reasoning Example:
January has been cold here in Siberia. Today is January 14, so it is going to be another cold day in Siberia.

27. Say this
Not this
Look at how those people are behaving. They must be mad.
Those people are all mad.
All of your friends are good. You can be good, too.
Be good.
The base costs is XXX. The extras are XXX, plus tax at XXX. Overall, it is great deal at YYY.
It will cost YYY. This includes XXX for base costs, XXX for extras and XXX for tax.

28. Deductive Argument Conclusion: This wire will conduct electricity.
Premise: Everything made of copper conducts electricity.
Premise:
This wire is made of copper.
Conclusion: This wire will conduct electricity.

29. Weaknesses in Inductive Reasoning
There are two possible weaknesses in inductive generalizations. 1) the sample may not be representative of the population it is drawn from. Is the sample representative? 2) The sample may be too small, and thus there is a second question we should ask: Is the sample large enough? If the sample is unrepresentative or too small then the premises will be inadequate to support the conclusion.

30. Weaknesses in Inductive Reasoning
Sampling: Examples
Just one observation of the effect of cold metal on a human tongue is enough for most kids to form a good generalization.
Similarly, we need not observe the case history of every smoker who has ever lived in order to conclude that smoking is a health hazard.
On the other hand, someone who concludes that “all the good ones are taken” on the basis of two bad dates might sensibly be advised to keep looking.

31. The local branch of Wachovia Bank was robbed yesterday
The local branch of Wachovia Bank was robbed yesterday. Jenny needed money to pay off her gambling debts. She just bought a gun two days ago, and I saw her hanging around the local Wachovia Bank yesterday morning. Today the bookie’s goons stopped looking for Jenny. So Jenny robbed Wachovia Bank yesterday.
Inductive argument

32. Deductive Argument Premise: All turtles have shells.
Premise: The animal I have captured is a turtle.
Conclusion: I conclude that the animal in my bag has a shell.

33. Deductive Argument
Sherlock Holmes and Watson were on a camping trip. They had gone to bed and were lying there looking up at the sky. Holmes said, “Watson, look up. What do you see?”
“I see thousand of stars.”
“And what does that mean to you?”
“I guess it means we will have another nice day tomorrow. What does it mean to you, Holmes?”
“To me, it means someone has stolen our tent.”
Deductive reasoning drives you to a conclusion based on known facts.

34. Inductive argument
Premise: Tonya is seen walking from her car to her home with a set of golf clubs.
Premise: Tonya’s husband Jeff loves golf and tomorrow is his birthday.
Conclusion: Tonya has bought the set of golf clubs for Jeff.
Inductive reasoning depends on human observation.
Tonya, after all, may be borrowing the golf clubs. Or she may have taken up golf herself!
You wouldn’t know unless you observed carefully, and even then, you would have to describe your conclusion as “probable” but not firm.

35. Deductive argument
The cut-off date for swim camp registration is June 15. After that date, applicants go on a wait list - no exceptions allowed.
You have missed the cut-off to date to register by two days.
You won’t be registered and your name will go on the waiting list.

36. How do we tell inductive from deductive?
The distinction between inductive and deductive arguments is based on the strength of an argument’s inferential claim.
An inferential claim is based on a certain reasoning process – it is the relationship between the premises and conclusion of an argument.
But the strength of a claim is hardly ever stated outright, so we have to evaluate it.
Three criteria for measuring an argument’s strength:
1) The occurrence of special indicator words.
2) The actual strength of the inferential link between the premises and conclusion.
3) The form of argumentation used by the person making the argument.
Certain indicator words lean more towards inductive and some lean towards deductive. But they’re not always accurate. Pay attention to the context of the argument.
Example: The word “probably” tends to be used in inductive arguments, and words like “therefore” and “necessarily” tend to lean towards deductive arguments.
Inferences are the reasoning parts of an argument. Conclusions are a type of inference, but always the final inference. Usually an argument will be complicated enough to require inferences linking the premises with the final conclusion:
1. Doctors earn a lot of money. (premise) 2. With a lot of money, a person can travel a lot. (premise) 3. Doctors can travel a lot. (inference, from 1 and 2) 4. I want to travel a lot. (premise) 5. I should become a doctor. (from 3 and 4)
Here we see two different types of claims which can occur in an argument. The first is a factual claim, and this purports to offer evidence. The first two premises above are factual claims and usually not much time is spent on them — either they are true or they are not.
The second type is an inferential claim — it expresses the idea that some matter of fact is related to the sought-after conclusion. This is the attempt to link the factual claim to the conclusion in such a way as to support the conclusion. The third statement above is an inferential claim because it infers from the previous two statements that doctors can travel a lot.
Without an inferential claim, there would be no clear connection between the premises and the conclusion. It is rare to have an argument where inferential claims play no role. Sometimes you will come across an argument where inferential claims are needed, but missing — you won’t be able to see the connection from factual claims to conclusion and will have to ask for them.
Assuming such inferential claims really are there, you will be spending most of your time on them when evaluating and critiquing an argument. If the factual claims are true, it is with the inferences that an argument will stand or fall, and it is here where you will find fallacies committed.
Unfortunately, most arguments aren’t presented in such a logical and clear manner as the above examples, making them difficult to decipher sometimes. But every argument which really is an argument should be capable of being reformulated in such a manner. If you cannot do that, then it is reasonable to suspect that something is wrong.

37. The Indicator Word Test
Nadia is a B.A (English) student. Most B.A. (English) students own laptops. So, probably Nadia owns a laptop.
The indicator word test asks whether there are any indicator words that provide clues whether a deductive or inductive argument is being offered.
Common deduction indicator words include words or phrases like necessarily, logically, it must be the case that, and this proves that.
Common induction indicator words include words or phrases like probably, likely, it is plausible to suppose that, it is reasonable to think that, and it's a good bet that.
In the example above, the word probably shows that the argument is inductive.

38. The Strict Necessity Test
No Texans are architects. No architects are Democrats. So, no Texans are Democrats.
The strict necessity test asks whether the conclusion follows from the premises with strict logical necessity. If it does, then the argument is deductive.
In this example, the conclusion does follow from the premises with strict logical necessity. Although the premises are both false, the conclusion does follow logically from the premises, because if the premises were true, then the conclusion would be true as well.

39. Forms of deductive arguments
Argument based on mathematics
The conclusion depends on a mathematical or geometric measurement.
Has to be deductive since it follows necessarily --- meaning there’s no room for it “probably” being right.
Example: 1+1 = 2
There’s no room for a different answer by reevaluating the argument will always equal 2. If you have 1+1, then it’ll always equal 2.
Argument from definition
The conclusion is claimed to depend on the definition of a word or phrase used either in a premise or in the conclusion.
They follow necessarily because the argument depends completely on the definition of the word being used.
Example: John is a kleptomaniac, so it follows forth that he steals things.
The argument is deductive since the definition of the word leads the argument to one conclusion alone.

40. More deductive forms Categorical syllogisms Hypothetical Syllogisms
A 3-line argument. Made up of exactly two premises and one conclusion. Begin with the words “all”, “some”, and “no”.
Example:
All oaks are trees*
All trees are plants
All oaks are plants .
Hypothetical Syllogisms
Syllogisms (two premises and one conclusion) that have a conditional statement for one (or both) of its premises.
If it rains, we will not have a picnic.
If we don't have a picnic, we won't need a picnic basket.
Therefore, if it rains, we won't need a picnic basket.
If you have A, then you have B.
If you have B, then you have C.
Therefore, if you have A, then you have C. .
Hypotheticals work like chains…one leads to the next and ties them all together

41. Inductive argument forms
Prediction
An argument that works based off our knowledge of the past in order to make a claim about the future.
Example:
There tends to be a lot of rain in the Midwest, so it will probably rain there tomorrow.
Claims about the future can’t be known with any certainty, so they can’t be absolutely true, even though they can be justified. That makes them inductive.
Argument from analogy
Depends on the existence of an analogy (or similarity) between two separate things.
My Honda gets good gas mileage.
So it follows that John’s Honda also gets good gas mileage.
The truth of an argument like this is based on chance, so and that chance makes it an inductive argument.

42. More inductive argument forms
Generalization
An argument that is applied to a whole group based on knowledge gained from a small sample of people.
Example:
Five out of ten people in Ellis Hall said they support abortion. So I can say that half of Athens supports abortion.
Statistical data is not always accurate, so the truth of this form of argument can not be made certain. It remains only probable.
Argument from authority
An argument that concludes something is true because an expert said it is.
Centrum vitamins work because Dr. Jones did a study that proved it.
This type of argument is only true with probability since studies can be wrong or mistaken.

43. Even more inductive argument forms
Argument based on signs
Conclusion based on knowledge gained from a sign about what the sign claims to mean.
Example:
A sign on the side of the road says “School Zone” so I can assume that a school is somewhere up ahead.
The sign could have been moved from somewhere else, or it could simply be wrong, so it can’t be true with absolute certainty.
Causal inference
Argument that proceeds from knowledge of a cause to a claim about its effect, or vice versa, that knowledge of an effect can provide information about its cause.
I left a soda in the freezer last night, so I can assume that it is frozen.

44. Is the argument below deductive or inductive?
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.

45. Tess: Are there any good Italian restaurants in town
Tess: Are there any good Italian restaurants in town? Don: Yeah, Luigi's is pretty good. I've had their Neapolitan rigatoni, their lasagne col pesto, and their mushroom ravioli. I don't think you can go wrong with any of their pasta dishes.
Is this argument deductive or inductive? How can you tell?
Inductive.
The argument is an inductive generalization, which is a common pattern of inductive reasoning. Also, the conclusion does not follow with strict necessity from the premises.

46. I wonder if I have enough cash to buy my psychology textbook as well as my biology and history textbooks. Let's see, I have $200. My biology textbook costs $65 and my history textbook costs $52. My psychology textbook costs $60. With taxes, that should come to about $190. Yep, I have enough.
Is this argument deductive or inductive? How can you tell?
Deductive.
This argument is an argument based on mathematics,
which is a common pattern of deductive reasoning. Plus,
the conclusion follows necessarily from the premises.

47. Mother: Don't give Billy that brownie
Mother: Don't give Billy that brownie. It contains walnuts, and I think Billy is allergic to walnuts. Last week he ate some oatmeal cookies with walnuts, and he broke out in a severe rash. Father: Billy isn't allergic to walnuts. Don't you remember he ate some walnut fudge ice cream at Melissa's birthday party last spring? He didn't have any allergic reaction then.
Is the father's argument deductive or inductive? How can
you tell?

48. Mother: Don't give Billy that brownie
Mother: Don't give Billy that brownie. It contains walnuts, and I think Billy is allergic to walnuts. Last week he ate some oatmeal cookies with walnuts, and he broke out in a severe rash. Father: Billy isn't allergic to walnuts. Don't you remember he ate some walnut fudge ice cream at Melissa's birthday party last spring? He didn't have any allergic reaction then.
Inductive.
The father's argument is a causal argument, which is a
common pattern of inductive reasoning. Also, the
conclusion does not follow necessarily from the
premises. (Billy might have developed an allergic reaction
to walnuts since last spring.)

49. John is an agnostic. It necessarily follows that he doesn't believe in God.
Is this argument deductive or inductive? How can you tell?
Deductive.
This argument is an argument by definition, which is a
common pattern of deductive inference. Also, the phrase
"it necessarily follows that" is a deduction indicator
phrase. Also, the conclusion follows from the premises.

50. Larry: Do you think Representative Miller will be re-elected
Larry: Do you think Representative Miller will be re-elected? Norman: I doubt it. Miller's district has become more conservative in recent years. Miller is a liberal Democrat, and 63% of the registered voters in his district are now Republicans.
Is this argument deductive or inductive? How can you tell?
Inductive.
This argument is both a statistical argument and a
predictive argument, which are two common patterns of
inductive reasoning. Also, the conclusion does not follow
necessarily from the premises.

51. If Buster walked to the game, then he didn't drive to the game
If Buster walked to the game, then he didn't drive to the game. Buster didn't drive to the game. Therefore, Buster walked to the game.
Is this argument deductive or inductive? How can you tell?

52. If Buster walked to the game, then he didn't drive to the game
If Buster walked to the game, then he didn't drive to the game. Buster didn't drive to the game. Therefore, Buster walked to the game.
Deductive.
This argument is a hypothetical syllogism, which is a
common pattern of deductive reasoning.
Note, however, that the conclusion does not follow logically from the premises. (Maybe Buster rode his bike to the game, for example.) The argument commits the fallacy of "affirming the consequent." X

53. Evaluating Arguments
Once you have an argument summarized/standardized, you need to evaluate it to see if you are forced to accept the conclusion.
There are two main questions to ask when doing so:
Is the argument a “good argument”?
Are the premises acceptable?

54. When is an argument a good argument?
What “good argument” does not mean:
“agrees with my views”
The attitude that only arguments that agree with your viewpoints are good is extremely close-minded.
“persuasive argument”
People aren’t always smart and can be persuaded by “eloquent speech” (and be confused by solid reasoning).
Hitler was more persuasive than Churchill, but that doesn’t mean that Hitler’s arguments were better.
“well-written/spoken”
Although it’s easier to tell whether an argument is good if it is well written, being well written doesn’t make it good. Clarity, eloquence and organization can all occur in the presence of logical mistakes.

55. When is an argument a good argument?
What “good argument” does mean.
It must, at the least, be either deductively sound (valid with true premises) or inductively cogent (strong with true premises).
In a nut shell, a good argument embodies all the good qualities of critical thinking.

56. When is an argument a good argument?
But it will also need to be clear…
An argument isn’t good unless it is understandable.
…precise…
One needs to avoid equivocation and use exact language.
…the premises need to be relevant…
Arguments with a lot of irrelevant material can’t be said to be good arguments.
…consistent…
Arguments that contain logical contradictions commit the fallacy of inconsistency.
…complete…
If an arguer ignores facts relevant to the conclusion at hand, we can’t say the argument is good (it doesn’t account for relevant objections).
…and fair.
An argument can’t be good if it hastily dismissed objections.

57. Evaluating Arguments What is a good argument?
A good argument (2 conditions) - All premises are true, and the premises provide good reasons to accept the conclusion.
An argument is deductively valid if the conclusion must be true if the premises are true.
An argument is inductively strong if the conclusion is probably true if the premises are true.
A good argument, fundamentally, is an argument
that is either deductively sound or inductively cogent.

58. What is a good argument? An argument that satisfies the
A good argument from the standpoint of critical thinking is:
The most important critical thinking standards are:
Accuracy – Are all the premises true?
Logical Correctness – Is the reasoning correct? Is the argument deductively valid or inductively strong?
Also, other critical thinking standards must be taken into account, including clarity, precision, relevance, consistency, completeness and fairness.
An argument that satisfies the
relevant critical thinking standards
that apply in a particular context.

59. Evaluating Arguments General Guidelines
Are the premises true? relevant to the conclusion?
Is the reasoning correct? Is the argument deductively valid or inductively strong?
Does the arguer commit any logical fallacies?
Does the arguer express his or her points clearly and precisely?
Are the arguer’s claims logically consistent? Do any of the arguer’s claims contradict other claims made in the argument?
Is the argument complete? Is all relevant evidence taken into account (given understandable limitations of time, space, context and so on)?
Is the argument fair? Is the arguer fair in his or her presentation of the evidence and treatment of opposing arguments and views?

60. Evaluating Arguments
An argument is deductively valid if the conclusion must be true if the premises are true.
An argument is inductively strong if the conclusion is probably true if the premises are true.
Dylan is a man. He is 99 and is in a coma. Therefore, Dylan will not run in the marathon tomorrow.

61. Example of deductively valid argument
All monkeys are primates
All primates are mammals
So, all monkeys are mammals
the following argument is not valid:
If Sue misses her plane she will be late for the conference.
Sue is late for the conference.
Therefore, she missed her plane.

62. When is it reasonable to accept a premise?
Arguments always contain premises, and—while some premises will have support from other premises—there will always be some premises that are mere assumptions (claims made by the arguer).
If the argument is valid/ strong, its soundness/cogency will turn on whether these assumptions are true. So how can we tell if we should accept them?
The Principle of Rational Acceptance

63. The Principle of Rational Acceptance
Evaluating Arguments
When is it reasonable to accept a premise?
In general, it is reasonable to accept and unsupported claim as true when:
The claim does not conflict with personal experiences that we have no good reason to doubt,
the claim does not conflict with background beliefs / information that we have no good reason to doubt, and
The claim comes from a credible source.
The Principle of Rational Acceptance
People often place too much trust in their own observation and experiences.
Personal experiences are often less reliable than we think. We need to be aware that “believing” is often “seeing” and that things are not always as they appear.
Critical thinkers recognize that their beliefs, hopes, fears,
expectations, and biases can affect their observations.
Critical thinkers think very carefully about the beliefs they accept.
Never believe without sufficient evidence and never believe more
strongly than the evidence warrants. – Watchwords of the wise.
Background beliefs – A vast network of conscious and unconscious convictions we use as a framework to assess the credibility of claims that can’t be verified directly.
“It was snowing in Kuala Lumpur last 31st August.”
“It was raining in Kuala Lumpur last 31st August.”

64. My dog is “as gentle as a kitten.” Got it!
Evaluating Arguments
1. Does the Claim Conflict with our Personal Experiences?
People often place too much trust in their own observation and experiences.
Personal experiences are often less reliable than we think. We need to be aware that “believing” is often “seeing” and that things are not always as they appear.
My dog is “as gentle as a kitten.” Got it!
Really?
Critical thinkers recognize that their beliefs, hopes, fears,
expectations, and biases can affect their observations.

65. Evaluating Arguments
1. Does the Claim Conflict with our Personal Experiences?
But it should be noted that your senses are not indubitable (un-doubtable). They can be mistaken for any number of reasons.
Bad physical conditions (e.g., poor lighting)
Sensory impairment (e.g., poor vision)
Observer impairment (e.g., drunk)
Unreliable measuring instruments
Bad memory
People often place too much trust in their own observation and experiences.
Personal experiences are often less reliable than we think. We need to be aware that “believing” is often “seeing” and that things are not always as they appear.

66. How reliable are your senses?

67. How reliable are your senses?

68. Evaluating Arguments
2. Does the Claim Conflict with our Background Beliefs?
Background beliefs - convictions held—usually assumed without question—that inform most of the other beliefs that we have
This seems to contradict our background belief that it doesn’t snow in deserts during the summer
It snowed in Las Vegas last July 4th
Sarah Parker is a robot.
This contradicts our background belief that people aren’t robots.
But it is important to note that even background beliefs should be subject to revision if sufficient evidence is presented against them (don’t be dogmatic about any beliefs you have) e.g. It snowed in London last July.

69. Exercise
For each of the following unsupported claims, indicate whether or not it would be reasonable to accept the claim. Also, state the criteria you use in reaching your decision.
Is the claim consistent with my personal experiences?
Is the claim consistent with my background beliefs / convictions?
Black cats bring bad luck.
98% of statistics are just made up.
I read the entire Encyclopedia Britannica last summer (said by a stranger at a party).
There is no hard scientific evidence that smoking is addictive (said by a tobacco company executive).
Ghosts really exist.
Aliens have visited the earth in some form.

70. 3. Does the claim come from a credible source?
Questions to ask to determine source credibility:
Genuine expert?
Are they outside their area?
Are they biased?
Do they have a reason to lie?
Questionable senses (were they drunk)?
Are they generally reliable (is it The Enquirer? )
Right context?
Can expert opinion settle the issue (e.g., is this a moral issue)?
Is it improbable?
An expert authority?
In their field of expertise?
Biased or with a motive to lie / mislead?
Source’s observations / experiences reliable?
The source itself reliable?
Source cited incorrectly or out of context?
Issue unable to settle by expert opinion?
Source is highly improbably?

71. Evaluating Arguments Is the source a genuine expert or authority?
3. Does the Claim Come from a Credible Source?
Is the source a genuine expert or authority?
Does the source speak in his or her area of expertise?
Is the source biased or has some other motive to lie or mislead?
Is the accuracy of the source’s personal observations or experiences questionable?

72. Evaluating Arguments
Does the Claim Come from a Credible Source?
Is the source contained in a source that is generally unreliable (e.g. gossip magazine) ?
Has the source been cited correctly or has been quoted out of context?
Is the issue one that can be settled by expert opinion?
Is the claim made by the source highly improbable on its face?
Critical thinkers must ask, “Are all premises true?” and “Do the premises provide good reasons to accept the conclusion?”

73. Fallacies
A form of reasoning that is illogical or violates the rules of valid argument
*hasty generalization
"I have dated three women from FBMK, and they all had tempers. Therefore, all female students from FBMK have tempers."
This is a hasty generalization because three is not a large enough sample size to accurately determine the temper of all redheads.
A generalization based on too little evidence or on exceptional or biased evidence.

74. Dicto Simpliciter (Sweeping Generalization)
Making a sweeping statement and expecting it to be true in every specific instance
The result is stereotyping.
The problem is that the sweeping statement may be true in many cases, but it is not necessarily true in every case. Thus the conclusion would be invalid for those exceptions.
"Scientists are closed-minded. If something doesn't fit into one of their formulas or laws, they won't even consider it as being possible or even be willing to study it to find out the truth."

75. Non Sequitur (It does not follow)
Caused by invalid deductive reasoning
Non Sequitur (It does not follow)
A statement that does not follow logically from what has just been said—a conclusion that does not follow from the premises.
Faulty: Susan is smart; therefore she will receive good grades.( Many smart people do not receive good grades.)
"If you do not buy this type of pet food, you are neglecting your dog."

76. Caused by invalid deductive reasoning
Either ….or
The writer states that only two alternatives exist when in fact there are more than two.
Faulty: A mother may tell her child: “Eat your broccoli or you won’t get desert.”
An ignorant friend might say: “I’m not a doctor, but your runny nose and cough tell me that you either have a cold or the flu.”
Children need this type of black and white structuring until they can learn to make valid choices.  These types of arguments become fallacious, however, when they reduce a complicated issue down to simple terms or when they deliberately obscure other alternatives.  Either/Or choices can also assume the form of scare tactics.  Sometimes, poorly-written multiple-choice tests contain these fallacies: sometimes the student can justify more than one correct choice, given different circumstances.
Well, the only truth about the above statement is that the speaker is not a doctor.  Although most people with these symptoms really do have the common cold or a touch of the flu, these options are not the only two available.  Allergies, bronchitis, or thousands of more serious diseases could all display these two common symptoms.  See your doctor for a diagnosis without relying on overgeneralizations or either/or fallacies.

77. Circular Reasoning
Circular reasoning is an attempt to support a statement by simply repeating the statement in different or stronger terms. The reason given is nothing more than a restatement of the conclusion that poses as the reason for the conclusion.
Faulty: A confused student argues: “You can’t give me a C. I’m an A student!”
An obvious non-smoker blurts: “Can a person quit smoking? Of course — as long as he has sufficient willpower and really wants to quit.”
A confused student argues: “You can’t give me a C.  I’m an A student!”
Circular reasoning is problematic because the claim is made on grounds that cannot be accepted as true — because those very grounds are in dispute.  How can a student claim to be an A student when he just earned a C?
To clarify, no one is an “A student” by definition.  Grades are earned in every class and are derived from a variety of different methods.  The requirements in one class are set by the school and the instructor, so the same class taught by a different teacher or in a different location should yield two very different results (final grades).  Merely claiming to be an A student does not make the claim valid.
NOTE: The false authority fallacy also applies here — you cannot use yourself as your own authority with total certainty.  A doctor is more qualified to diagnose your shoulder pain than you are; your teachers are better qualified to evaluate your performance than a student.  
An obvious non-smoker blurts: “Can a person quit smoking?  Of course — as long as he has sufficient willpower and really wants to quit.”
This statement contains a more subconscious version of circular reasoning.  The intended argument simply repeats itself, disguised as a logical statement.  The warrant is simple: “A person can quit because he can.”  True, any smoker can quit, but the task is not as obvious or as easy to accomplish as the statement suggests.  The arguer must provide reasons to suggest how a person can overcome an addiction, not to simply identify the obvious use of will power.  This example also falls into distortion and the only reason fallacies.  

78. Bandwagon
An argument saying, in effect, "Everyone's doing or saying or thinking this, so you should, too.“
Faulty: Everyone else is drinking, so why shouldn't I?(The majority is not always right.)

79. Hominem
Attacking the person who presents an issue rather than dealing logically with the issue itself
Faulty:
His arguments might impress us if we were not aware of how he treats his children. (The man's alleged unfatherly behavior need not invalidate his arguments.)

80. Red Herring
Dodging the real issue by drawing attention to an irrelevant issue.
Faulty:
Why worry about a few terrorists when we ought to be doing something about acid rain?
Acid raid has nothing to do with the actions of terrorists.)

81. Any Questions?

82. THANK YOU