Transcript How do we find out?

What is Science?
Psyc 362 Research Methods in Psychology
Chapter 2
James A. Van Slyke
S
Historical Roots
S 1920’s Logical Positivism and the Vienna Circle
S Attempting to distinguish between science and metaphysics
(problem of demarcation)
S Attempting to reconstruct all scientific knowledge from experience –
empiricism – ‘bottom-up’
Philosophical Roots
S Karl Popper (1902-1994)
S Scientific theories are those theories that are falsifiable
S Scientific theories should continually be in competition
S Those theories that withstand continued experimentation are
vindicated
Philosophical Roots
S Carl Hempel (1905-1997)
S “hypothetico-deductive” method in science
S A hypothesis is accepted or rejected according to its ability to explain
data
S Hypothesis are never proven is a straight-forward manner, dependent
upon how much later research supports or rejects it
The Scientific Method
Theory
Hypothesis
Data
 Theory

A scientific theory explains through an integrated set of principles that
organizes and predicts behaviors or events
The Scientific Method
Theory
Hypothesis
 Hypothesis

Identifying a testable prediction based on the theory
Data
The Scientific Method
Theory
Hypothesis
Data
 Testing
Doing the actual research by application of the hypothesis
 Using statistics to infer characterizations

The Scientific Method
Theory
Hypothesis
 All three interconnected
Separate, yet inform each other
 Method moves in a circle

Data
Progress in Science
S Imre Lakatos (1922-1974)
S Science progresses through competing research
programs
S
Composed of theories, hypotheses and data
S Research programs progress by explaining data
over time
S Explain data better than a competing programs
The Logic of Scientific Discovery
S Law
S Theory
S Hypothesis
The Logic of Scientific Discovery
S Law- universal statement about the nature of things
that allows reliable predictions of future events
S The most significant laws in science are the laws of
conservation
S Energy- total amount of energy in an isolated system remains
constant
S Momentum- tendency of an object to continue to move in its
direction of travel unless acted upon by an outside force
The Logic of Scientific Discovery
S Theory- a general statement about the causal
relation between two or more variables
S Must adhere to the canons of science
S Theory of evolution
S Theory of classical conditioning
S Principle of equifinality- the same behavior is
often produced by many different causes
The Logic of Scientific Discovery
S Hypothesis- prediction about a specific event derived from
one or more theories
S If the prediction does not prove true, what does this mean in
regards to the theory?
The Science of Observation
S Induction vs Deduction
The Science of Observation
S Induction- reasoning from specific instances to general
principles
S Method of Induction- making many observations under
controlled conditions and arriving at a general statement
S Francis Bacon
The Science of Observation
S Problem of Induction- How do you know when you’ve
made enough observations to be sure that a theory can be
labeled a law, i.e. that it will always be true.
S David Hume- it is always possible that the very next
observation could violate previous conclusions regardless of
the number of observations that you make.
The Science of Observation
S Deduction- reasoning from general principles to specific
instances
S Deduction in science- when theories are used to develop
hypotheses that are then tested against observations.
Three Approaches to Hypothesis
Testing
S Validation
S Falsification
S Qualification
Three Approaches to Hypothesis
Testing
S 2-4-6 task
If a card has a vowel on one side, it must have
an even number on the other side.
96% of participants give wrong answers on this problem
Three Approaches to Hypothesis
Testing
S Positive Test Bias (Confirmation Bias)- tendency for people
who are evaluating hypotheses to attempt to confirm rather
than disconfirm these hypotheses.
S Behavioral Confirmation- tendency for social perceivers to
elicit behaviors from a person that are consistent with their
initial expectancies of the person.
If a person is drinking an alcoholic beverage then they must be over
21 years of age.
Three Approaches to Hypothesis
Testing
S Validation- researchers attempt to gather evidence that supports
or confirms a theory or hypothesis
S Falsification- researchers attempt to gather evidence that
invalidates or disconfirms a theory or hypothesis
S Qualification- researchers attempt to identify the boundary
conditions under which a theory or hypothesis is and is not true
The Art of Scientific Discovery
S Inductive Techniques for Developing Ideas (reasoning from the
specific to the general)
S Case studies
S Paradoxical incidents
S Analyzing the practitioner’s rule of thumb
S Serendipity
The Art of Scientific Discovery
S Deductive Techniques for Developing Ideas (reasoning from the
general to the specific)
S Reasoning by analogy
S Applying a functional or adaptive analysis
S Hypothetico-deductive method
S Accounting for conflicting results
S Accounting for exceptions