How do we know things? The Scientific Method Psych 231: Research Methods in Psychology
Jan 03, 2016
Announcements
Why is this page upside down? Does the course webpage show up in
ReggieNet? Quiz 1 is due Friday Aug 21st @
midnight• Anybody try quiz 1 yet? Does it work okay?
Lab news This week labs are in their usual places,
next week they will be meeting in the library. Milner 164D computer classroom
The Science of Mythbusting
Accept the myth or Test the myth
Testable hypotheses – is the phenomenon something that can be observed and tested
Method – what is best way to make the observations to be tested?
Control groups – comparisons are key Replication – are you more likely to believe something that
happens once, or happens multiple times
Are elephants afraid of mice? long (~8 min)
Exercise: How do we know?
Write down two things that you “know”. Write down HOW you “know” those things.
“Greatest football team ever”
• Coach Bill Walsh
• Joe Montana & Jerry Rice
• 5 Superbowls
1981 1984 1988 1989 1994
Methods of Inquiry
Objective Subjective
Analysis
AcceptanceAuthority
Instruction
Regulation (rules & laws)
Tenacity
Faith
Intuition
Type of knowledge
Way
s of
kno
win
ghaving existence outside of a
person’s mind (“real”)existing in a person’s mind
Persuasion
Rationalism
Deduction
Our focus
Empiricism
Observation
Scientific Method
Reality is not this clear cut: Psychology uses objective techniques to examine what are often subjective things, so there are often some underlying assumptions that you need to keep in mind (later in the course: indirect measures, operational definitions)
Reality is not this clear cut: Psychology uses objective techniques to examine what are often subjective things, so there are often some underlying assumptions that you need to keep in mind (later in the course: indirect measures, operational definitions)
Methods of Inquiry
The Scientific Method A method used to test and analyze claims
about behavior Uses systematic observation and
experimentation 4 Cannons of the Scientific method:
• Empiricism, Determinism, Parsimony, Testability A 6 step process (your book breaks it into 7
slightly different steps, Figure 2.1)
Scientific Method
Step 1: Observation (Empiricism) Pay attention to the world around you, look for
generalizations
write down two generalizations that you have observed about people’s behavior
Two classes of generalizations• Descriptive generalizations – just describe how it is/what
was seen, how frequent, without making predictions• Cause and effect generalizations – makes predictions about
the observed relationship between two (or more) things.• (Determinism: phenomenon have identifiable causes)
Scientific Method
Step 2: Develop a theory or hypothesis Identify the variables associated with your
observations
Variables The characteristics of the behavior and the surrounding context
An explanation for the observed behavior(s)• How are the variables related to one another?
• May be based on past research, common sense, intuition, logic, etc.
Scientific Method
Step 3: Generate a testable prediction Testability: Need to specify how your hypothesis can
be tested through observation.• The relevant variables must be defined and observable.
Falsification is at the heart of the scientific method• Scientists don’t try to prove a theory, but rather set out to
refute (“disprove”) theories • Refutable hypotheses - must be stated in a way that allows
the potential for it to be wrongKarl Popper wiki
Scientific Method
Step 4: Make systematic observations Observational and experimental methods
• Which variables will we examine?• How do we measure these variables?• Which variables can we systematically manipulate?• What variables need to be controlled?• Were (from whom) will we collect the observations?
Scientific Method
Step 5: Evaluate your evidence Refutes theory Supports theory (not “proves the theory”) Leads to the revision of the theory Consider alternative theories
• There are always alternative explanations• Parsimony: Simple explanations are preferred over
more complex ones
Scientific Method
Step 6: Repeat
observations
hypotheses
predictions
systematicobservations
newhypotheses
predictions
systematicobservations
newhypotheses