Critical Thinking Analysis of an Argument

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Critical Thinking- Analysis of an Argument

• G.P. Taylor, Ph.D.
• University of Texas at San Antonio

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Critical Thinking

• The use of those cognitive skills or strategies
  that increase the probability of a desirable
  outcome.
• It is used to describe thinking that is
  purposeful, reasoned and goal directed
• solving problems
• formulating inferences
• calculating likelihoods
• making decisions
• Involves evaluating the thinking process
• What reasoning that went into the conclusion?
• Sometimes called directed thinking because it
  focuses on a desired outcome."
• Halpern, Diane F. Thought and Knowledge An
  Introduction to Critical Thinking. 1996.

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Critical Thinking II

• Deciding rationally what to or what not to
  believe
• Norris, Stephen P. "Synthesis of Research on
  Critical Thinking. Educational Leadership, v 42 n
  8 May 1985. 40-45.

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Critical Thinking III

• Careful and deliberate determination of whether
  to accept, reject, or suspend judgment.
• Moore and Parker, 1994.

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Critical Thinking IV

• The purpose of critical thinking is
• to achieve understanding
• evaluate view points
• solve problems.
• Thus, critical thinking is the questioning or
  inquiry we engage in when we seek to understand,
  evaluate, or resolve."
• Maiorana, Victor P. Critical Thinking Across the
  Curriculum Building the Analytical Classroom.
  1992.

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GRE Examination

• Writing Component In
• Logical Reasoning Out
• Writing Component incorporates critical thinking
• Analysis of an Argument
• Presentation of an Issue

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In Science, Critical Thinking is used when you

• Observe problem/phenomenon/conceive ideas
• Develop a hypothesis
• Make predictions Formulate experiments
• Test Predictions Carry out experiments/analyze
  data
• Draw conclusions from results, modify hypothesis
• Modify as needed and do again.
• Reject or confirm hypothesis
• The Scientific Method itself involves critical
  thinking
• VITAL for a scientist.
• Impressive for a science student
• Need to have time to read and think

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Scientists are Natural Skeptics

• Big thing to learn during Grad school
• Be critical of everything!
• Are their ideas supported by the literature?
• Are their techniques correct?
• Did they analyze their data correctly?
• Are their conclusions supported by the data?

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Here, well practice being critical

• 7 exercises from the GRE questions pool
• Identify major problems with given argument
• Jot down, to discuss during class
• Dont share until during class
• Closed at time of class (no late)

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Example

• Last year the local television news program In
  Focus reported in its annual car-and-truck safety
  survey that over the course of the last 10 years,
  United Motors vehicles were in involved in at
  least 30 fewer fatal accidents to drivers than
  vehicles build by any other single manufacturer.
  Now, United is developing a one-of-a-kind kind
  computerized crash warning system for all its
  trucks. Clearly, anyone concerned with safety
  who is in the market for a new truck this year
  should buy a United Motors truck.

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How to Approach?

• Given There are flaws? What are they?
• Where are the problems?
• Analyze line of reasoning
• Consider questionable assumptions
• Does evidence support the conclusion?
• What additional evidence is needed to strengthen
  or weaken argument?
• What other info is needed to evaluate the
  conclusion?

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Common Types of Logic Flaws

• Weak analogy between two things
• Confusing correlation or timing issue with cause
  and effect
• Over-generalizing characteristics of individuals
  to groups
• Assuming that a certain condition is necessary or
  sufficient for outcome
• Relying on questionable statistics
• Assuming that things dont change with time
• Making a recommendation based on narrow
  either-or reasoning, when there are other
  obvious solutions

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Weak Analogy

• Conclusion about one thing, based on success or
  failure of anotherwith many other variables
  present
• Ex Biotechnology company doing well in SAIll
  open one as well

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Confusing Cause and Effect

• Ice cream consumption leads to criminal behavior
• Other factors Summer heat, out of school, etc

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Necessary and Sufficient

• Necessary- No other ways of getting effect
• Sufficient- Alone can cause effect
• ex. Lets do this (presents only one option-
  another course may be better). May require
  additional efforts (teacher effort, etc)

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Unrepresentative Statistics

• Sample large enough
• Sample representative of overall population in
  relevant characteristics
• How many are needed?
• What works theredoes it here?

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Assuming no change over time

• Old stats may not been representative of today

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Narrow Either-Or Reasoning

• Must choose only one path
• Perhaps both courses of action are okay?
• Are other courses of action feasible?

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What I Want

• Identify conclusion
• Identify supporting evidence
• Brainstorm and identify three or four discrete
  flaws (see prior slides), plus any others that
  you note, and the type of logic they are
  violating
• How to strengthen argument? (What additional info
  is needed)

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Example

• Last year the local television news program In
  Focus reported in its annual car-and-truck safety
  survey that over the course of the last 10 years,
  United Motors vehicles were in involved in at
  least 30 fewer fatal accidents to drivers than
  vehicles build by any other single manufacturer.
  Now, United is developing a one-of-a-kind kind
  computerized crash warning system for all its
  trucks. Clearly, anyone concerned with safety
  who is in the market for a new truck this year
  should buy a United Motors truck.

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Example

• Conclusion Truck buyers should favor the UM
  truck over others
• Evidence Presented
• Compiled TV station-calculated 10 year fatality
  rate on all UM vehicles
• Development of new truck safety system

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Logic Problems

• Survey
• Scope
• what fatal accidents included?
• Geographic effects (fewer UM vehicles In Focus
  local?)
• All vehicles, not trucks alone
• Non-fatal also relevant to safety
• Other assumptions
• No changes in truck safety over 10 years
• Maybe even UM worsewhy new system?
• Overall, perhaps fewer trucks sold (not rate
  data)
• Drivers of UM trucks safer than others
• The new Safety feature
• Is effective
• Is included on this years trucks

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To Strengthen the Argument

• Accident sample representative
• Other measures of safety (non-fatal)
• Past relative safety into present
• New safety features included and effective