Unformatted text preview: Research Methods
in Psychology I. The Scientific Method
I. The Scientific Method
A. Theory – Explanation that organizes and
B. Hypothesis – Specific, testable prediction.
C. Operational Definitions – The procedures
used in the research.
D. Replication – Repeating a study to see if
the original findings generalize to other
participants and situations.
* Psychology is a science.
Psychology II. Research Strategies
II. Research Strategies
1. Case Study
3. Naturalistic Observation
*Correlation – statistic used for descriptive
or pseudo-exp. studies
C. Experimentation Description Case Study
Description Case Study
One or a few individuals is studied in depth in
the hope of revealing universal principles.
Examples: study of serious brain injury (H.M.),
Freud’s theory of personality, Piaget and child
Limitations: Any given individual can be
atypical, therefore it becomes easy to make
- Description Survey
- Must use a representative, random sample.
Examples: dating practices, political polls, drug
Limitations: sampling errors, response rate.
The best basis for generalizing is not from the
exceptional cases at the extremes, but from a
representative sample of cases.
representative Description Naturalistic Description Naturalistic Observation
Observing and recording behavior in naturally
occurring situations without direct intervention
Examples: Jane Goodall and chimps, child
interactions at playgrounds, pace of life
(Levine & Norenzayan, 1999)
Limitations: does not explain behavior
- Rank Country Rank Country Rank Country 1 Switzerland 11 France 21 Greece 2 Ireland 12 Poland 22 Kenya 3 Germany 13 Costa Rica 23 China 4 Japan 14 Taiwan 24 Bulgaria 5 Italy 15 Singapore 25 Romania 6 England 16 U. S. 26 Jordan 7 Sweden 17 Canada 27 Syria 8 Austria 18 S. Korea 28 El Salvador 9 Netherlands 19 Hungary 29 Brazil 10 Hong Kong 20 Czech Rep. 30 Indonesia 31 Mexico Adapted from Levine, R.V., & Norenzayan, A. (1999). The pace of life in 31 countries. Journal of CrossCultural Psychology, 30(2), 178205. Correlation
A statistical measure of the extent to which two
factors predict each other.
Examples: intelligence and achievement? IQ and
drug use? extraversion and risk-taking?
Why do we use correlation?
When experimentation is unethical.
When experimentation is impossible or too
When you’re looking at traits that can’t be
Limitation: Does correlation mean causation?
An investigator manipulates one or more
factors (independent variables) to observe the
effect on some behavior or mental process (the
Experimental Condition – exposes participants
to the exp. treatment.
- Control Condition – serves as a comparison
for evaluating the effect of the treatment.
Independent variable (IV) – the exp. factor that
is manipulated; the variable whose effect is
Dependent variable (DV) – the exp. factor that
is being measured; the variable that may
change in response to manipulations of the
Be careful of extraneous variables! 1..
4. Effects of stress on diet?
Effects of group size on willingness to speak up?
Effects of nagging on completion of chores?
Effects of sleep on cognitive skills? ...
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- Spring '08
- Psychology, representative, Levine, II. Research Strategies