Critical thinking fall 2014 2015 (chapters 6,7,8,11 and 12 analyzing and evaluating an argument) for students

1

CRITICAL THINKING

I. Chapters 6, 7, 8, 11 and 121.Fallacies of Insufficient Evidence (Chapter 6)2.Analyzing Arguments (Chapter 7)3.Evaluating Arguments (Chapter 8)4.Inductive Reasoning (Chapter 11)5.Finding, Evaluating and Using sources (Chapter 12)II. Application of Critical thinking

Analyzing and Evaluating an Argument

3

How reliable are your senses?

4

How reliable are your senses?

5

Structures of an Argument(DEDUCTION and INDUCTION)

INDUCTIVE CONCLUSION 1

DEDUCTIVE CONCLUSIONSTRICT LOGICAL NESCESSITYPREMISE(S)

PREMISE(S) LIKELY OR PROBABLY

Conclusion 2

Conclusion 3

6

DEDUCTIVE REASONING

Chapter 4

INDUCTIVE REASONING

Chapter 4

THE VALIDITY OF DEDUCTIVE REASONING

THE VALIDITY STRENGTHOF INDUCTIVE REASONING

VEEN DIAGRAMChapter 9

TRUTH TABLEChapter 10

FALLACIES(Chapter 5, 6)

EVALUATIINGARGUMENT

(Chapter 7, 8, 11, 12)

ARGUMENTChapter 1,2,3

(VALID or INVALID)

Mistakes inReasoning and Evidences

Strong or Weak

7

The concept of RelevanceEx 1: Babara is a traditional woman(p*). Thus, she may enjoy cooking

(C1).If (p*) is TRUE then we can see (C1) is TRUE. => (p) is relevant to (C1)Ex 2: Dog are Cat (q*). Cat are feline (r*). So, Dog are feline (C2) If (q*) and (r*) are TRUE then (C2) is TRUE. (p) and (r) are relevant to (C2)

Ex 2: Cherios is a good student(s*). Because he knows how to cheat on exams(C3).

If (s*) is TRUE then (C3) is FALSE

(s) is relevant to (C3)

A RELEVANT PREMISE: If it TRUE, it can help you to know the conclusion is TRUE or FALL

A positively relevant premise = A premise (even TRUE or FALSE) gives the logically conclusive reason for accepting the conclusion p, q, r are positive relevant premisesA negatively relevant premise = the premise, if TRUE, gives reason for thinking the conclusion is FALSE s is a negative relevant premise

Irrelevant premisesEx 3: Tom likes playing piano (p*). Therefore, he may like cooking(C).Ex 4: UCLA is one of the best universities in USA. So, we can see the American

educational system is too open.

(p*) Do neither support nor against (C)

=> A statement is irrelevant to another when it counts neither support to nor against that other statement.

8

9

“Strong” or “weak” inductive argument

Argument 1:We can conclude that children are

innocent. Because they are friendly, they love everyone and always believe in adults.

Argument 2:We can conclude that children are

innocent. Because they are friendly and always believe in adults.

Argument 3:

Argument 3: We can conclude that children are innocent. Because they are very dependent and need to be educated.

What is the strong inductive argument?

- All premises are positive relevant to the conclusion.

-The conclusion follows necessarily from the premises.

10

“Analyze”, “Diagram” and “Evaluate” an inductive argument

Argument 1: We can conclude that children are innocent(C). Because they are friendly(p*), they love everyone(q*) and always believe in adults(r*).

Argument 2:We can conclude that children are innocent(C). Because they are friendly(p*) and always believe in adults(r*).

Argument 3: We can conclude that children are innocent(C). Because they are very dependent(s*) and need to be educated(t*).

C

rqp

C

p r

C

s t

11

“Strong” or “weak” inductive argument

Argument 1: We can conclude that children are innocent(C). Because they are friendly(p*), they love everyone(q*) and always believe in adults(r*).

Argument 4: We can conclude that children are innocent(C). Because they are friendly(p*), very dependent(s*), they love everyone(q*) and always believe in adults(r*)

C

r*q*P*

C

r*q*P* s*

Logically Irrelevant PremiseHuman is mortal. Bill Gate is human. So, Bill Gate is mortal. I am not Bill Gate.

Thus, I am not mortal.Analyze the argument, we have:Human is mortal(p*). Bill Gate is human(q*). So, Bill Gate is mortal (C1). I am

not Bill Gate (s*). Thus, I am not mortal (C2).

12

C1

C2

p q

s

p q

C1 s

C2

13

Decide which of the individual piece/s of information would strengthen the argument if added

Having students work in groups lets them practice the skills they are learning. It is an efficient way to develop their active learning.

a) Speaking in front of the whole class can be scary. b) Breaking students up into groups not only develops social skills useful in

the professional environment for which they are trainingc) Most of good students say that they do not get any benefits from group

workd) Group work gives students a chance to perform in a supportive

environment that help them to become more confident.e) Students who like to clean on others feel comfortable in group work.f) Most of students improve their communication skills via group work.

14

Having students work in groups lets them practice the skills they are learning. It is an efficient way to develop their active learning.

a) Speaking in front of the whole class can be scary. b) Breaking students up into groups not only develops social skills useful in

the professional environment for which they are trainingc) Most of good students say that they do not get any benefits from group

workd) Group work gives students a chance to perform in a supportive

environment that help them to become more confident.e) Students who like to clean on others feel comfortable in group work.f) Most of students improve their communication skills via group work.

Answer

Refuting Arguments

Lecture Notes © 2008 McGraw Hill Higher Education 15

ARGUMENT

PREMISE/S CONCLUSION

TRUE

FALL

Logicallyfollow the premise/s

Not follow the premise/s

AND

OR

WE REJECT THE ARGUMENT

WE ACCEPT THE

ARGUMENT


Refuting Arguments

There are two ways to refute an argument:1) Show that a premise—or a critical

group of premises—is false or dubious.

2) Show that the conclusion does not follow from the premises.

APPLICATIONS OF CRITICAL THINKING

1) Learning: critique on information and experiences2) Research, Project, Paper: product logical reasoning,

make deductive and inductive argument, use sources, references…

3) Life: evaluate information to make right decisions, recognize fallacies

4) Work: Make decisions => (Plan-Do-Check-Act)

Application:Structure of your Group Presentation and Final Paper

Structure of your Group Presentation and Final Paper

• Cover: Topic, Group and Students name• Index• Content:Page 1-2: Introduction the importance of Topic (Requirement: For each argument you must show the source of

references)EX: Many Vietnamese students have shock culture when studying abroad

(Nguyen, 2012)


Page 2-4: Present your research questions and Questionnaire

(Requirement: Use Diagrams to show the relationship between each research question and survey questions)

Research Question 1:…..

Survey question 1:…



Research Question 1: How do IU students think about to

study in Vietnam?

Survey question 1: What do you think are advantages when studying VN?

Survey question 2: What do you think are advantages when studying VN?

What are FALLACIES you can commit in your questions?


I agree with you that we are very tired …

OKKKK…I see you think that both of them can’t be a

good president

Are you tired of Bronco Bamma and Mitt Romney and they can’t be good presidents?

Examples• Question 1: Do you agree that homosexual and same sex marriage

should be accepted? (YES/NO)• Question 2: Do you think that Vietnamese educational curriculums

and teaching methods now are update? (YES/NO)• Question 3: Can you see that Tom can not answer my question and

he is a bad student ?


1) Loaded question are multiple questions “rolled up” into one1 and 2 are “Fallacies of Loaded question”2) The arguer asks a question that contains an “unfair” or “unwarranted presupposition”=> 3 is “Fallacies of unwarranted presupposition”


“Fallacies of unwarranted presupposition”

EX 2: Do you think automobile makes the transportation in HCM city go from bad to worse?

EX 3: Why did you cheat on your exams?

EX 4: Have you stopped cheating on your exams?


Inductive Generalizations

• Generalization: statement made about all or most members of a group.

• Inductive generalization: inductive argument that relies on characteristics of a sample population (i.e., a portion of the population) to make a claim about the population as a whole. – i.e., an inductive argument with a generalization as a

conclusion. • Example: All the catfishes caught in Mekong river have

been less than 1lb. So, most of the catfishes caught in the Mekong river are less than 1lb.


• Page 4-5: Describe your targets Describe:- people who answer your questionnaire and your interviewees - the method of collecting information (how do you choose your

target, how do you contact them, what tool you use to record data…)

• What are FALLACIES you can commit in your sampling?


Sorry, we don’t have it. You can either buy an HP

or Vios laptop, but you don’t want a Vios, so you

must buy an HP.I am looking for a

Dell laptop

Fallacy of False Alternatives


If you don’t elect me, then the rate of jobless will increase. I’m sure that you don’t want the rate of

jobless will increase. So, elect me!

What now can prove that after you select him, the

rate of jobless will be decrease. Obama’s

argument is a fallacy of False Alternative.


False Alternatives

• False Alternatives = when an argument says there are only “n options” when there are actually “more than n”.

• What are FALLACIES you can commit in your sampling?- You can not interview the people that can give you accurate

information, thus, you interview your friends, roommates!


Hasty Generalization

• …occurs when one draws a general conclusion from a sample that is biased or too small. – Biased sample: I polled 1,000 American scientists,

only 25 of them believed in God. I guess most Americans don’t believe in God anymore.

– Too small of a sample: I asked 05 professors at VNU if they believed in their students, and all of them did. It can be seen that most professors in VN believe in their students.


Some students I have met in University of Technology speak English better than IU students. I think students of University of Technology speak English better than IU students.

Research on climate change in South-Eastern Region in Vietnam shows that the climate change cause by industrial pollution. Based on this, we can conclude that the climate change in Mekong Delta Region is caused by the algricutural pollution.

Fallacy of Hasty Generalization

Taking notes• Focus on your aims Be clear about your project aims, the purposes of your interview... and

note all issues that relate to your aims or purposes.• Be accurate Note exactly what you heard, read, see without any bias• Be precise Note in details what you heard, read, see • Be clear=> Use clear language when noting


Page 5-10: Present the results of Questionnaire (Describe how do you analyze data; use statistics analysis and pie chats or graphs) and and present your explanations of the results

Page 10-12: Present the results from Interviews (select the adequate quotes from the interviews) and your explanations of the results


Page 13-15: Introduce each research question and the answer for it that follow the results.

EX: 1) Research question 1:What students think about homosexual?From the research, it can be conclude that most students

perceive homosexual a desease. A few of the know the effects of social environment that can cause homosexual.

What are fallacies you can commit in your conclusion?


Statistical Arguments

• Statistical arguments go “the other way.” They take generalizations and draw conclusions about smaller samples of the population (usually individuals).

• Example:1. You’re a college student 2. 90% of college students want no cumulative final.3. So you probably don’t want a cumulative final.

• The more “broad” the conclusion the better.• The higher the original percentage, the better. • Usually, if the percentage is around 50%, we will call the

argument unreliable, even if it is more likely than not that the conclusion is true.

– A “rule of thumb”: if it is would reasonable to bet on it, then it is reliable.

Making Inductive Generalizations stronger by making conclusions weaker.

• Ex 1: All the catfishes caught in Mekong river have been less than 1lb. So, all the catfishes caught in the Mekong river are less than 1lb.

• Ex 2: All the catfishes caught in Mekong river have been less than 1lb. So, most of the catfishes caught in the Mekong river are less than 1lb.

=> stronger



Johnson: We have to conclude that Mr. A‘s corruption did

happened. Because no one has proven that there was not !

No one has prove this doesn’t mean it is true !

Johnson’s argument is “a fallacy of appeal

to ignorance”


Appeal to Ignorance

• Appeal to Ignorance = Fail to prove something false and then, conclude that it is true (or visa-versa). – e.g., There must not be cheating in IU exams. We

have never found any. Note:Special rules: e.g., “innocent” until “proven guilty”.


Last week, I eat a lot of garlic that were cooked together with fried seafood, and this morning I see my skin was dry! It is clear that garlic made skin dry.

Fallacy of Questionable CauseQuestionable Cause occurs when one claims, without sufficient evidence, that one thing is the cause of something else.


Oversimplified cause fallacy

EX 1: There are 2.5% students of chemistry class cheat on their exam. That shows the chemistry lectures were not good.

(Students cheat because they did not understand the lectures; or they are lazy to learn…)

- Oversimplified cause fallacy: suggesting that A is the cause of B when clearly B has many causes.


Questionable Cause

• EX 2I drank the ginseng tea and I

was better by the next day. The tea must have made me better.

• The post hoc fallacy: suggesting that A causes B just because A came before B.


Questionable Cause

• EX 3:I every morning this week I

ate bananas, and every day I failed an exam. I should stop eating bananas so I can pass my exams.

• Mere correlation fallacy: suggesting that the constant conjunction of A and B entails that they are causally related.


My father is tall, friendly and intelligent, he is very faithful to

my mother. My boy friend is tall, friendly and intelligent. So, he will

be very faithful to me.

Fallacy of Weak Analogy


The Slippery Slope

• …fallacy is committed when one claims, without sufficient evidence, that a seemingly harmless action will lead to a terrible one. – e.g., Dr. Perry has proposed that we legalize physician-assisted

suicide. No sensible person should listen to such an proposal. If we allow physician-assisted suicide eventually there will be no respect for human life.

• Common form: A leads to B, and B leads to C, and C to do D, and we really don’t want D. Thus, we shouldn’t do A.

• Exception: – If one presents good evidence that “A” will lead to “D,” and if D

should be avoided, then the conclusion that A should be avoided is justified.


Inconsistency

• …the fallacy of inconsistency is committed when an arguer espouses two logically contradictory claims. – e.g., Nobody goes there anymore; it’s too crowded.

• Common form– A and not A.

• The only exceptions to this rule are equivocations: – Bob is dead even though he isn’t.

• If you mean “he’s emotionally dead, even though he isn’t physically dead” then you are not contradicting yourself… you are just being unclear (by being ambiguous).

• But the exact same thing can never be both true and false at the same time.


Tom’ s argument is “a fallacy of Inappropriate appeal to authority”

Tom: My barber says that Einstein’s general theory of relativity is a lot of hogwash. So, Einstein wasn’t

as smart as everybody think he was

Prof Brenda: The source (the barber) is not a genuine authority on the subject at issue (Einstein’s general theory)


Examples• Ex 1: “In recent years, there is a trend towards homosexual in

Vietnamese young people”. (Tran Vinh - Tuoitre online). => Do you think that this can be used as a fact?• EX 2: “Hotels in Vietnam are really good”, a tourist says. Do you think that this can be used as a fact?• 3: My friend who is studying in FPT University says that it is the best

university in Vietnam.=> Do you think that this can be used as a fact?


Inappropriate Appeal to Authority

• Inappropriate Appeal to Authority = citing an authority who is unreliable.

• Ways we can question reliability:– Are they an authority/expert? – Are they biased? – …

Using sources and References

• Scientific books (Who is its author?)• Scientific Journals (See its impact factors?)• Research (check the research methodology)• Database (National Database, …)

Using sources and References1. Use the source to get information2. References for your statementsEX 1: In Vietnamese education, mathematics has been seen as a system of rules and

algorithms taught to students without references to its origin and cultural setting. Mathematics is taught from the so-called mechanistic point of view, providing pupils with static and clear-cut knowledge (Wubbels, Korthagen, & Broekman, 1997).

ReferencesWubbels, Th., Korthagen, F. A. J., & Broekman, H. G. B. (1997). Preparing teachers for

realistic mathematics education. Educational Studies in Mathematics, 32, 1–28.EX: Many Vietnamese students have shock culture when studying abroad (Nguyen,

2012)ReferencesNguyen. A Tuan, Studying the trend to study abroad of Vietnamese students, Journal

of International Education, 32, pp.23-35.

Paraphrase

• Paraphrase : to make longer arguments becomes tedious => ParaphrasingEX: Many people are smoking. You are smoking also. I see you smoke a lot every day.

That can damage your lung and cause you cancer.1. Be accurate: don’t misrepresent2. Be clear: Take un-clarity and make it clear3. Be Concise: get to the bare essentials4. Be Charitable

– Bad paraphrase: Cigarette smoking guarantees that you will get lung cancer. Continue to smoke and you will be unhealthy.

– Good paraphrase: Cigarette smoking is a positive causal factor that increases the risk of lung cancer. Therefore, if you continue to smoke, you risk being unhealthy.


Standardization• Standardization: Finding missing premises and conclusions

• EX: Many people are smoking. You are smoking also. I see you smoke a lot every day. That can damage your lung and cause you cancer.

=> Paraphrase: Cigarette smoking is a positive causal factor that increases the risk of lung cancer. If you smoke, you risk being unhealthy.

• e.g., I see you are smoking a lot everyday (missing premise). Cigarette smoking is a positive causal factor that increases the risk of lung cancer. Therefore, if you continue to smoke, you risk being unhealthy.

Announcement• Group presentation: DEC 22nd - 31st 2014 or after Final Exam

(check your email to get the schedule of your group presentation informed by Mrs. Thao)

• Date of Critical thinking final exam: JAN 5th 2014• Deadline to submit your final paper: JAN 12th 2015• Group evaluation (use the evaluation form in the Guideline):

have a group meeting to evaluate each members (his/her contribution to the group presentation and final paper) and attach the evaluation form to your final paper.

=> Individual score (A:100% the group score; B: 75%; C;50% and D:0%)