Research Methods in Social
Psychology


I. Develop a research question
II. Develop a hypothesis

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A hypothesis is a testable prediction that
describes relationships between events.
III. Research Design

Operational definitions specify how to
measure concepts.
Research Methods in Social
Psychology (cont.)

A. Correlational Research Designs
Correlation involves assessing the relationship
between two or more variables
 Correlation coefficient ranges from -1 to +1

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Number gives the strength of the relationship
Sign gives the direction of the relationship
Interpreting correlational results:
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Correlation does not imply causation!
Two problems in establishing cause-effect:
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Directionality problem – Does A cause B or
does B cause A?
Third variable problem – C may cause both A
and B
Evaluating Research


Internal Validity: the degree to which a
research finding provides clear or
compelling information about causality.
External validity: the degree to which a
research finding provides an accurate
description of what typically happens in
the real world.
Evaluating Research (cont.)



To increase the external validity of a laboratory
study, increase:
Mundane realism: degree to which the
experimental conditions resemble real-world
situations.
AND/OR
Experimental realism: degree to which the
experimental conditions are psychologically
engaging.
Experimental Research


Studies that seek to establish cause-effect
relationships by manipulating one or more
factors while holding others constant.
Independent variable (IV) – the variable that is
manipulated by the experimenter.



Experimental group – treatment
Control group – no treatment
Dependent variable (DV) – the variable that is
measured as an outcome.
Experimental Research (cont.)

Two essential ingredients of an
experiment:


Random assignment – each participant has an
equal chance of being in the experimental
group or the control group
Holding the other variables constant – the
only difference between groups should be the
manipulated variable: Everything else must be
held constant
Factorial Design

A design in which the levels of 2 or more
independent variables are completely
crossed.
Main effect

A statistical term meaning that, overall, an
independent variable has an effect on a
dependent variable.
Interaction


A statistical term meaning that the effects
of one independent variable on a
dependent variable depend on the level of
another independent variable.
The effects of _____ on _______ depend
on ______.
Taunting No
Taunting
High
Skill
8
7
8
8
M=8
Low Skill 4
6
M=5
M=6
6
Taunting
5
4
3
No
Taunting
2
1
0
High
Skill
Low
Skill
M=7
Violent
Game
Non-violent
game
High
hostility
6
4
M=5
Low
hostility
2
4
M=3
M=4
M=4
6
5
4
Violent
Non-violent
3
2
1
0
High Hostility
Low Hostility
Violent
Game
Non-violent
Game
High
hostility
7.5
6.5
M=7
Low
Hostility
6.5
5.5
M=6
M=7
M=6
8
7
6
5
Violent
Non Violent
4
3
2
1
0
High Hostility
Low Hostility
Ethics



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1. Deception is allowed, but the benefits of the
research must outweigh the costs.
2. If deception is used, participants must be
promptly debriefed at the end of the
experiment.
3. Researchers must obtain informed consent.
Participants are to be informed of any risks of
benefits of participating in the study and that
they may withdraw at any time without penalty.
4. Researchers must ensure the confidentiality of
data.