Experimental Psychology

1
Experimental Psychology

• Psychological Science as a Way of Knowing
• Spring 2004

2
What is Experimental about Experimental
Psychology?

• Defining feature of discipline when it was first
  established
• It is not about the psychology of experimentation
• Use of scientific research methods
• Psychology as a science

3
A Brief History of Experimental Psychology

• The personal equation in astronomy
• The measurement of touch and muscle sense
• Measurement of attention
• Measurement of memory
• 1879 - official date of first psychology
  laboratory, established by Wilhelm Wundt

4
Brief History, contd

• 1878 G. Stanley Hall receives PhD from William
  James at Harvard
• 1882 Hall gets job at Johns Hopkins
• 1886 Cattell is first American to receive PhD
  from Wundt
• 1888 Hall becomes president of Clark University,
  focused on graduate education in psychology
• 1889 Cattell becomes professor of psychology at U
  of Penn

5
Features of Science

• Systematic empiricism
• Publicly verifiable knowledge
• Solvable problems
• The falsifiability criterion
• Utility as truth

6
Systematic Empiricism

• What is empirical?
• Based on observations of the world
• Examples gorillas, And No Birds Sing, Clever
  Hans
• What is systematic?
• Sampling is specified
• Recording is systematic

7
Public Knowledge

• Results can be obtained by someone else using the
  same methods
• no special talents
• Confirmable by others
• interobserver reliability
• Use of external memory
• Record does not depend on a memory

8
Solvable Problems

• Problems can be approached using currently
  available methods
• finding treatments for AIDS
• localizing a brain tumor
• Some problems cannot be solved
• video-recording someones dream
• preventing hurricanes

9
Falsifiability Criterion

• Logical analysis of arguments
• Valid arguments
• Internal Validity
• External Validity
• Logical Forms
• Modus ponens
• modus tollens
• affirming the consequent
• denying the antecedent

10
Falsifiability Criterion

• Karl Poppers analysis
• Hypothesis testing
• seeking contrary outcomes
• the importance of negative evidence
• when positive evidence is important

11
Science as a Utilitarian Endeavor

• Truth versus truth
• The necessary uncertainty of induction
• The constructed reality of science

12
Fallibility of Science

• Thomas Kuhn and the structure of scientific
  revolutions
• Science as a human enterprise
• Science as a way of knowing

13
Ways of Knowing

• Knowing by Belief or Intuition
• Knowing by Authority
• Knowing by Reasoning
• Knowing by Common Sense
• Knowing by Scientific Inquiry

14
Knowing by Belief

• Examples
• Knowing that sugar causes hyperactivity
• Believing in alien abductions
• Advantages
• Sense of certainty
• Provides understanding of the world
• Disadvantages
• Belief may be wrong
• Belief may not be shared by others
• No way to resolve differences between conflicting
  beliefs

15
Knowing by Authority

• Examples
• Mt. Everest is tallest mountain
• Your brain weighs about 3 pounds
• Richard Nixon is dead
• Advantages
• Quick
• Easy to acquire
• No responsibility for knowledge
• Disadvantages
• Authority may be wrong
• No way to resolve differences between conflicting
  authorities

16
Knowing by Reasoning

• Examples
• Knowing that 2 apples remain if 3 are taken from
  5
• Knowing that bumblebees cannot fly
• Advantages
• Certainty of conclusion
• Avoids costs and effort of doing things
• Disadvantages
• Reaching conclusion may be difficult
• Premises may be in error, and therefore
  conclusion will be in error

17
Knowing by Common Sense

• Examples
• Knowing that the earth is round
• Knowing that boys will fight
• Advantages
• Knowledge is shared by others
• Knowledge is easily accessible
• Knowledge can be tested against experience
• Disadvantages
• Knowledge may be wrong
• Knowledge is unsystematic
• Knowledge may be self-contradictory

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Knowing by Scientific Inquiry

• Examples
• Knowing that adrenalin increases heart rate
• Knowing that women have a double standard
• Advantages
• Knowledge can be shared by others
• Basis for knowledge can be evaluated and
  differences in claims can be resolved
• Disadvantages
• Knowledge is not certain
• Knowledge can take a long time to acquire

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Goals of Science

• Description
• Prediction
• Control
• Understanding

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Description as a Goal

• Examples
• Jane Goodall, describing behavior of chimpanzees
  in Gombe
• Oliver Sacks, describing disorders of
  brain-injured patients
• Gary Klein, describing decisions made by
  firefighters and air traffic controllers

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Prediction as a Goal

• Clinical forecast for patients
• Forensic prediction of behavior on release
• Prediction of cognitive performance

22
Control as a Goal

• Changes in health related behaviors (smoking
  cessation, exercise)
• Loss of phobic fear
• Action on command

23
Understanding as a Goal

• Sigmund Freud
• Project for a Scientific Psychology
• Clark Hull
• Principles of Behavior
• William Estes
• Stimulus sampling theory
• Herb Simon Allen Newell
• General Problem Solver