Transcript Experimentation - Barrington 220

Chapter 1
Psychological Science
Experimentation
Experimentation

Experiment


an investigator manipulates one or more
factors (independent variables) to observe
their effect on some behavior or mental
process (the dependent variable)
by random assignment of participants the
experiment controls other relevant factors
Theory

Seeing violence on TV causes children to
behave violently in real life.
Hypothesis

If children watch a violent TV show, they
will be more likely to act violently than if
children do not watch a violent TV show.
Operational Definitions

If children watch a violent TV show, they
will be more likely to act violently than if
children do not watch a violent TV show.
Children
 watch
 violent TV show
 more likely
 act violently
 non-violent TV show

Experimental Design
children who will
Experimental • 50
watch a violent TV
Group
show
Population
100 children
ages 5-8
Control
Group
Random
Assignment
• 50 children who will
watch a non-violent
TV show
Independent variable
• Children will play in
50 children
a play room for 30
watch violent TV
show
minutes
• Children will play in
50 children
watch nona playroom for 30
violent TV show
minutes
Record
evidence of
violent
behavior
Record
evidence of
violent
behavior
Dependent variable
Experimentation

Placebo


an inert substance or condition that may be
administered instead of a presumed active agent,
such as a drug, to see if it triggers the effects
believed to characterize the active agent
Double-blind Procedure

both the research participants and the research
staff are ignorant (blind) about whether the
research participants have received the treatment
or a placebo
 commonly used in drug-evaluation studies
Experimentation

Experimental Condition


the condition of an experiment that exposes
participants to the treatment, that is, to one
version of the independent variable
Control Condition

the condition of an experiment that contrasts
with the experimental treatment
 serves as a comparison for evaluating the effect
of the treatment
Experimentation

Random Assignment

assigning participants to
experimental and control conditions
by chance
 minimizes pre-existing differences
between those assigned to the
different groups
Experimentation

Independent Variable

the experimental factor that is manipulated
 the variable whose effect is being studied

Dependent Variable

the experimental factor that may change in
response to manipulations of the independent
variable
 in psychology it is usually a behavior or mental
process
Experimentation
Design an experiment that would test the effects of alcohol consumption on
hand-eye coordination. Be sure to include how your subjects are selected and
assigned, the control and experimental conditions, independent and dependent
variables, as well as any extraneous or confounding variables.