Lecture 1

1
Lecture 1 Outline

1. Why science?
2. The scientist as skeptic
3. Characteristics of scientific method
4. Working assumptions of science
5. Goals of science
6. Psychology as science

2
Why science?

• Science arose as a way of learning about how the
  world works

• It arose as an alternative to listening to
  authority
• Authority is very often wrong.

3
Why science?

• Why is authority so often wrong when it comes to
  answering important questions about how the world
  works?

• Because authority doesnt have any mechanism for
  testing and improving its ideas

4
Why science?

• Religious authority

• Religious authorities offer answers to our
  questions, but they dont offer evidence
• You have to take their answers on faith.
• Scientists dont do that.

5
Why science?

• Galileo rejected the geocentric view of the
  universe
• Galileo based his ideas on repeatable observations

6
Why science?

• Religious authority
• Intellectual authority

• Someone who wants you to accept a claim because
  he says its true
• Doesnt invite debate
• Doesnt have a way of testing his ideas

7
Why science?

• Newtons laws only work for objects moving
  relatively slowly
• If Newton could be wrong, then anyone can be wrong

8
Why science?

• Max Planck
• His physics professor told him to go into
  something else because physics is over in
  1875!

9
Why science?

• There is nothing new to be discovered in physics
  now. All that remains is more and more precise
  measurement.
• Lord Kelvin (1894)

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The scientist as skeptic

• If Newton and Kelvin could be wrong, then anyone
  of us can be and will be wrong.

• But being wrong isnt a bad thing.
• Whats bad is to be wrong and not know that
  youre wrong.

11
Why science?

• The scientists value system emphasizes skepticism

• All claims must be empirically tested
• All conclusions are tentative

12
Why science

• Science offers both
• an existing knowledge base of answers and
• a procedure for testing and improving those
  answers

• Scientists dont ask you to take their word for
  it
• They offer you evidence and invite you to check
  it for yourself

13
The scientist as skeptic

• Because we want to know when our ideas are wrong,
  we value skepticism and we test our ideas.

• We also avoid ad hominem arguments.

14
Ad hominem arguments

• Ad hominem argument means attacking the person
  youre arguing against
• It questions a persons intelligence, motive, or
  character.

• Ad hominem attacks suggest that winning an
  argument is the most important thing
• It isnt.

15
A recent example

• Green party leader Elizabeth May recently used
  the granddaddy of ad hominem arguments when she
  compared the Tories to Nazis

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Ad hominem argument

• Godwins Law
• The moment you compare your opponent to the
  Nazis, youve lost the argument.

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Why is this approach wrong?

• When you compare your opponents to Nazis, youre
  saying, These people disagree with me because
  they are bad people.

• This takes the focus off your ideas and puts it
  on your opponents character
• That is a recipe for failure

18
Ad hominem argument

• Ad hominem attacks are poor substitutes for an
  argument
• Theyre used by people who dont have anything
  better to offer.

• If they did have anything better, they would use
  it.

19
What should we do?

• Think of people who disagree with you as
  intelligent, concerned people who look at the
  evidence on a given issue and reach different
  conclusions than you do.

• Respect your opponent and rise to the challenge
  of countering their arguments.

20
The values of this classroom

• We learn from people who disagree with us
• Freedom of inquiry and freedom of speech are
  essential to science

• Ideas are valued to the extent that they survive
  empirical testing
• All topics, without exception, are open to
  discussion

21
The values of this classroom

• Freedom of inquiry and freedom of speech are
  hallmarks of science.
• We learn from people who disagree with us.

• No-one is wise enough to decide for the rest of
  us what we can say and what we shouldnt say.
• Trying to prevent people from speaking is the
  strategy of people who dont have a good argument.

22
Characteristics of scientific method

• Empirical approach

• We resolve disputes by appeals to data

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Characteristics of scientific method

• Empirical approach
• Objective reporting

• We state our findings and conclusions plainly and
  fairly, without marketing

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Characteristics of scientific method

• Empirical approach
• Objective reporting
• Operational definitions

• We define concepts in terms of the procedures for
  measuring them
• E.g., IQ

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Characteristics of scientific method

• Empirical approach
• Objective reporting
• Operational definitions
• Tentative conclusions

• The current model may be disconfirmed by future
  discoveries

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Characteristics of scientific method

• Empirical approach
• Objective reporting
• Operational definitions
• Tentative conclusions
• Systematic observation

• We strive to make unbiased observations
• We observe relevant phenomena

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E
K
4
7
If a card has a vowel on one side, then it has
an even number on the other side. Which cards
would you turn over to determine whether this
claim is true?
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E
K
4
7
If a card has a vowel on one side, then it has
an even number on the other side. Turn over E
7 to test the hypothesis they allow
disconfirmation. The scientist makes progress by
putting his theory in jeopardy.
29
Characteristics of scientific method

• Precise instruments

• We use not the most precise instruments
  available, but instruments of the appropriate
  degree of precision

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Characteristics of scientific method

• Precise instruments
• Valid and reliable measurements

• Reliable means repeatable
• Valid means were measuring what we think were
  measuring

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Characteristics of scientific method

• Precise instruments
• Valid and reliable measurements
• Testable hypotheses (fallibility)

• If no imaginable result would prove our theory
  wrong, then the theory is useless.
• It cant be tested, so cant be improved

32
Characteristics of scientific method

• Precise instruments
• Valid and reliable measurements
• Testable hypotheses (fallibility)
• Skeptical attitude

• If Newton could be wrong

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Characteristics of scientific method

• Precise instruments
• Valid and reliable measurements
• Testable hypotheses (fallibility)
• Skeptical attitude
• Parsimony (Occams Razor)

• If more than one theory accounts for some data
  equally well, choose the simplest theory

34
Science working assumptions

• Reality of the world

• The world is real
• Contra see Nick Bostroms work on the world as
  simulation
• Contra Bishop Berkeley objects exist because
  God perceives them

35
Science working assumptions

• Reality of the world
• Rationality

• world is understandable (logical)
• there is a system to the world

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Science working assumptions

• Reality of the world
• Rationality
• Regularity

• world is consistent
• Newton so impressed people because he showed that
  gravity on Earth and in space were the same
  force the same laws of physics work in all times
  and places

37
Science working assumptions

• Reality of the world
• Rationality
• Regularity
• Discoverability

• The world is knowable
• It is a puzzle, not a mystery
• Not only is there a system to the world, but we
  can discover that system
• But doing so is a challenge!

38
Science working assumptions

• Reality of the world
• Rationality
• Regularity
• Discoverability
• Causality

• Events have causes
• Determinism vs. randomness
• Free will?

39
Science Goals

1. The Discovery of Regularities

• Description what are the phenomena to be
  explained?
• Important for a young science

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Science Goals

• The Discovery of Regularities

• Discovering laws
• A law is a regular relationship between two
  events
• Doesnt have to be causal

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Science Goals

• The Discovery of Regularities

• Search for causes
• Time order
• Covariation
• Plausible alternatives

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Science goals

• Development of Theories
• A theory

• Describes relationships among variables
• Has at least one unobservable concept
• Is falsifiable

43
Science goals

• Development of Theories
• A theory

• Organizes knowledge and explains laws
• Predicts new laws
• Guides research by
• Defining terms
• Suggesting new experiments
• Suggesting new approaches

44
Is psychology a science?

• Arguments for

• Empirical method
• Systematic observation
• Objective reporting
• Falsifiable hypotheses

45
Is psychology a science?

• Arguments against

• The thing being studied is the thing doing the
  studying

46
Review

• Scientific method settles disputes by appealing
  to objectively verifiable data.
• Therefore, science requires careful observation.

• Scientific method demands clear definitions,
  testable hypotheses, and a skeptical attitude.
• Nothing is sacred. Everything is debatable.