Scientific Method

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Scientific Method

• January 11, 2006

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How do we know things?

1. Tenacity
2. Intuition
3. Authority
4. Rationalism
5. Empiricism
6. Science

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Tenacity

• Habit or possibly superstition
• Example Only alcoholics can counsel other
  alcoholics
• Exposure The more we see something the more we
  like it
• Tenacity
• Make no guarantee of accuracy
• Has no mechanism for error correction

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Intuition

• An approach that does not utilize inference or
  detailed reasoning
• No way of determining what is accurate vs.
  inaccurate
• Can be very helpful in suggesting an hypothesis
• But can be very misleading.

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Authority

• Accepting knowledge because of respect for the
  source
• Some types of authority
• Government
• Parents
• Religion
• Employer
• No way to validate or question the knowledge
• Not the same as asking an expert we can accept,
  reject, or challenge the statements of an expert.

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Rationalism

• Knowledge through reasoning
• Logical deduction
• Assume knowledge is correct if correct process is
  used.
• Important for theory and pure math.
• Also logic puzzles like Sudoku
• Rationalism is useful to arrive at an hypothesis
  then use scientific method to test hypothesis.

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Example of Rationalism

• Premise
• All dogs like chewing on bones
• Lassie is a dog
• Conclusion
• Therefore Lassie likes chewing on bones

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Some Logical Fallacies

• Ad hominem (directed at the person)
• Ad antiquitatem (to tradition)
• Ad ignorantiam (to ignorance)
• Ad logicam (to logic) aka straw man
• Ad miscericordiam (appeal to pity)
• Ad populum (appeal to public)
• Ad numerum (appeal to numbers)

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Some More Logical Fallacies

• Complex questions
• Have you stopped beating your wife?
• Cum hoc ergo propter hoc
• With this, therefore because of this
• Nearly identical to post hoc ergo propter hoc
• After this, therefore because of this
• Mistakes correlation for causation
• Red herring
• Tu quoque
• You too
• Defending an error in ones reasoning by pointing
  out the opponent made the same erro.

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Empiricism

• Knowledge through experience
• I have experienced thus it is true

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Science

• Testing ideas empirically according to a specific
  set of procedures that is open to public
  inspection
• Based on objectively observed evidence
• Sans personal beliefs, perceptions, biases,
  attitudes or emotion

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Scientific Method
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Scientific Method

• Step 1 Observation
• Make an observation
• Most people in Florida with HIV/AIDS have
  financial difficulties.
• Inductive reasoning based on observation, make
  a general statement
• People with HIV/AIDS have difficulty maintaining
  employment and medical benefits.

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Scientific Method

• Step 2 Form an hypothesis
• Explain you observation
• Basically, this is your generalization from Step
  1, but it may be more refined.

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Scientific Method

• Step 3 Use hypothesis to generate a testable
  prediction
• Deductive reasoning make a specific prediction
  based on your hypothesis
• Example When given a choice between two
  equally competent employees, one with HIV and the
  other without, most employers would hire the
  individual that is not HIV positive than the one
  who is HIV positive.

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Scientific Method

• Step 4 Design the study
• The most creative part
• Who are your participants
• Design experimental, quasi-experimental,
  post-hoc, cross-sectional, longitudinal?
• This should be in part directed by the hypothesis
  or research question.

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Scientific Method

• Step 5 Conduct the study
• Record what happens
• Make systematic observations

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Scientific Method

• Step 6 Perform hypothesis testing
• Analyze you data with appropriate statistics
• Use the observations to support, refute, or
  refine your hypothesis.
• Example Employers in the skilled trades are
  less likely to hire an individual that is HIV
  positive versus employers of unskilled or
  professional workers.

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Scientific Method

• Science is empirical
• Science is public
• Science is objective

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Scientific Method

• Being a scientist is not related to what you
  study
• only HOW you study it!