Critical Thinking Skills

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Critical Thinking Skills

• ITK 214

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Quick Review

• Foundations of Inquiry
• Contained instruction in critical thinking
• Analyzing arguments
• Introduce you
• Academics
• Research
• Argument development

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Quick Review

• Use the skills in this class
• Discuss
• Social Legal and Ethical Implications of
  Information Technology

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Terms

• Argument
• Defined as - The offering of reasons or evidence
  in support of conclusion

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Terms

• Parts of an argument
• Premise
• Conclusion

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Terms

• Premise - Reasons, evidence, data used in support
  of the claim that the conclusion is true

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Terms

• Conclusion - The point that someone is trying to
  show is true or correct

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Review

• Diagram of an argument

Premise
Conclusion
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Evaluate an Argument

• Determine the strength of the argument
• Effectiveness
• Two methods of argument evaluation
• Premise Evaluation
• Argument Types

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• Premise evaluation
• Two methods to evaluate the premise
• Facts that support the conclusion

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Evaluate an Argument

• Premise evaluation
• Is the premise correct

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• Requires that you have knowledge of the topic
• Baseball
• Argument
• Babe Ruth hit 714 home runs in his career. Babe
  Ruth is the home run king.
• Fact is correct Babe Ruth hit 714 HR

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• Logical Evaluation

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Evaluate an Argument

• Logical Evaluation
• Does the premise lead to the conclusion
• A direct link between the premise and the
  conclusion

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• Argument
• Babe Ruth hit 714 home runs in his career. Babe
  Ruth is the home run king.
• There is a direct link

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Logical Evaluation

• Faulty Logic
• The price of eggs is 99 cents. Therefore,
  General Motors makes a better truck than Ford
  Motor Company.
• No link

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Logical Evaluation

• California has some very strict environmental
  rules. They passed some additional rules on auto
  pollution.
• When asked to comment one auto company released
  this statement

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Logical Evaluation

• They are putting the needs of the environment
  ahead of the needs of the people.

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Problem with Logical Evaluation

• Premise can be correct - factual
• Premise can lead directly to the conclusion.
• Conclusion can be false.

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Premise Evaluation

• Argument appear sound
• Babe Ruth hit 714 home runs in his career. Babe
  Ruth is the home run king.

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Logical Evaluation

• But
• Hank Aaron hit 755 home runs

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• This seemingly sound argument is false
• Babe Ruth hit 714 home runs in his career. Babe
  Ruth is the home run king.

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Another Example
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Logical Evaluation

• Premises.
• Iraq used WMD against the Kurds in the 1980s.
• Iraq had WMD in the first Gulf War.
• Iraq had WMD after the first Gulf War.
• Weapons inspectors found and destroyed some WMD
  in Iraq after the Gulf War.
• Some Iraqi WMD are unaccounted for.
• Iraq failed to allow inspectors to search for
  weapons.
• Iraq has been deceptive about the WMD.
• Conclusion..
• Iraq has WMD.

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• Weapons inspectors now agree that Iraq did not
  have WMD when the US invaded Iraq

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Evaluate an Argument

• To evaluate an argument on premises
• Premise must be correct
• Premise must lead to the conclusion

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Evaluate an Argument

• Evaluate on Faulty Reasoning

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• You do not need knowledge of the topic to
  evaluate reasoning
• You do have to listen..

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• Argument Types
• Forms of reasoning that appear in everyday life
• Logical fallacy

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Argument Types

• Ad Hominem Argument
• Attacking a critic of your argument rather than
  addressing the issue or the argument.
• Example Congressman Jim Trafficant of Ohio

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Argument Types

• Ad Hominem Argument
• Faulty argument because it attacks the speaker
  instead of the issue.

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Argument Types

• Slippery Slope Argument
• If Viet Nam falls to communism, so will Cambodia,
  Thailand, and all of southeast Asia. Eventually,
  Russia and the other communist countries will
  control all of Asia.

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Argument Types

• Slippery Slope Argument
• Faulty because one can hardly predict the future.
  You may be able to say that A will cause B.
• Beyond that it is speculation
• Example Viet Nam did fall-
• SE Asia is not under communist rule
• Developing democracy

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Argument Types

• Appeal to Authority
• Position
• Knowledge

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Argument Types

• Authoritarian Argument
• When asked about the possible number of US
  casualties in an Iragi war the Pentagon provided
  the following answer.
• That is an issue of national security. We cant
  discuss it.

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Argument Types

• Authoritarian Argument
• Faulty because
• Qualifications of the expert
• Do the qualifications relate to the topic

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Argument Types

• False Cause
• X causes Y
• B happened because A happened
• Cold weather causes flu.

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Argument Types

• False Cause
• Faulty because
• Confuse Correlation with Causation
• Example Cold weather causes flu.
• Flu virus is most virulent in cold weather

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Argument Types

• Fallacy of Composition/Division
• Composition
• Confuses the characteristics of the parts with
  the characteristics of the whole
• Because all the parts are good
• The whole must be good

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Argument Types

• Fallacy of Composition/Division
• Composition
• Example X brand uses all the best ingredients.
• X brand is best

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Argument Types

• Fallacy of Composition/Division
• Composition
• Faulty because the best parts do not always make
  the best whole.
• Social problems take the best qualified people
  provide a solution that does not work.

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Argument Types

• Fallacy of Composition/Division
• Division
• Characteristics of the whole is applied to the
  parts.
• Harvard is number one overall
• Harvard is number one in computer science

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Argument Types

• Fallacy of Composition/Division
• Division
• Faulty because no school can be the best at
  everything.

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Argument Types

• Ambiguity
• Using a word with more than one meaning
• Humans can think
• Computers can think
• Computers must be human
• Or humans must be computers

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Argument Types

• Ambiguity
• Computers have memory. Having memory allows us
  to recall childhood experiences. Therefore
  computers can recall experiences from their
  childhood.

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Argument Types

• Ambiguity
• The English language is imprecise.
• Must understand how a word is being used
• Take care not to change the meaning in the middle.

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Argument Types

• Appeal to the people
• There is strength in numbers
• Do not call list
• Declared unconstitutional
• Congress Debated
• 50 million Americans cannot be wrong

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Argument Types

• Appeal to the people
• Faulty because 50 million people can be wrong
• Germans supported Adolph Hitler
• 50 million people support George Bush
• 50 million people do not support George Bush

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• What did I just do?
• What kind of fallacy of argument did I just make?

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Argument Types

• Anecdotal evidence
• The Dodge Caravan mini van is the best mini-van
  in America. My Dodge mini-van has 175,000 miles
  on it. It runs well. There are no fluid leaks.
  The body has no rust. It will keep running
  forever.

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Argument Types

• Anecdotal evidence
• Faulty because anecdotes prove very little
• I owned 2 Dodge Caravans
• 140,000 miles
• Both dead

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Argument Types

• Generalization
• If someone likes it, everyone will like it.
• If a few people believe it, it must be true

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Argument Types

• Example My student attends ISU and has an A
  average. All students at ISU have an A average.

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Argument Types

• Generalization
• Faulty because of the variables involved
• Just not correct to say that because this happens
  to 10 people it will happen to everyone.

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Argument Types

• The Opinion Poll
• Characteristics of group
• Formulation of the questions
• When poll is conducted

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Sound Arguments

• There are very few really sound arguments that
  good premises, that are logical, and do not
  contain a fallacious argument.

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Strategy for evaluating an argument

• Identify the premise(s) and the conclusion

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Strategy for evaluating an argument

• 2. Test the logic
• Assume the premises are true
• Does these premises lead to this conclusion
• If there is a counterexample
• Is the argument valid?

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Strategy for evaluating an argument

• 3. Is this a sound argument?
• Are the premises true in the actual world?
• If so, the argument is sound

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Strategy for evaluating an argument

• 4. Is the argument invalid?
• Fallacious argument
• People use these
• Question the validity
• Cannot discard them

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Strategy for evaluating an argument

• 5. Evaluate the argument in general
• Best arguments are based on established facts
  that clearly relate to the conclusion.

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Class Discussion

• Argument Evaluation
• Look at two arguments