Testing a Claim with the Scientific Method
•Six
Basic Elements of the Scientific Method
–Observing
–Defining
a problem
–Proposing
a hypothesis (an educated guess that can be tested)
–Gathering
evidence/testing the hypothesis
–Publishing
results
–Building
a theory
•Hypothesis:
Testable hunch or educated guess about behavior
•Operational
Definition: States exact procedures used to represent a
concept. Allows abstract
ideas to be tested in real-world terms.
Creating operational definitions
•
–Which
of the following might be used as an operational definition of
“attraction?”
(1) A feeling of affection when two people are together.
(2)
The number of minutes during which two people are touching each
other over a four-hour period.
Variables
Any condition that can change and that might affect the outcome
of an experiment
•Independent Variable: Condition(s) altered by
the experimenter; experimenter sets their size, amount, or
value. These are suspected causes for behavioral differences.
•Dependent Variable: Demonstrates results of
the experiment. Condition is affected by independent variable.
•Extraneous Variables: Conditions that a
researcher wants to prevent from affecting the outcomes of the
experiment (e.g., number of hours slept before the experiment).
Conducting an experiment
To identify cause-and-effect relationships,
we conduct experiments.
A formal trial to confirm/disconfirm a hypothesis
–Directly vary a condition you think affects behavior.
–Create two or more groups of subjects, alike in all ways except
the condition you are varying.
–Record whether varying the condition has any effect on
behavior.
–Exert control over other extraneous variables that could vary
systematically with the manipulated variable (the independent
variable) so that differences in behavior are due to the
manipulated variable.
Types of experiments
•Single
Blind: Only the subjects have no idea whether they are
in the experimental or control group
•Double
Blind: The subjects AND the experimenters have no idea
whether the subjects are in the control or experimental group
–Best
type of experiment if properly set up
If the experimenter is aware of which
participants are in which group, how might this influence results in addition
to the independent variable?
If the participants are aware of which
group they are in, how might this influence results in addition
to the independent variable?
