“I have not failed. I have just found 10,000
things that do not work.”
Thomas Edison 1847-1931
CHAPTER 2:
PSYCHOLOGICAL SCIENCE
Amber Gilewski
Tompkins Cortland Community College
Two Types of
Research
Some elements
of good research
• Pure research
(for its own sake)
• Applied research
(used to solve
everyday
problems)
• Construct validity
(assess the
variables it’s
designed to
measure)
• Reliability
(consistency)
What makes psychological
research scientific?
• THEORIES: broad explanations
(example: diffusion of responsibility)
• HYPOTHESES: statements that allow
theories to be tested
• OPERATIONALIZATION: translating a
hypothesis into specific, testable procedures
that can be measured or observed
(i.e. anxiety, threatening situation, fear)
The Scientific Method
•
•
•
•
•
•
Formulate a research question
State the hypothesis
Test the hypothesis
Draw conclusions based on findings
Publish research
Replicate study
Scientific Method
Samples and Populations
• Sample
– Segment of population
• Population
– Entire group targeted for study
• Representative samples allow generalization of
findings
– Naturalistic observation: observes naturally
occurring behavior (i.e. Jane Goodall’s research)
– Case studies: in-depth investigation of an
individual or small group (i.e. profiles of serial
killers)
– Surveys: representative group asked questions to
assess ideas, attitudes, beliefs (i.e. political beliefs
questionnaire)
• Relationship between 2 sets of variables is
examined to see if there is a relationship
• Correlation coefficient between +1.00 & -1.00
• There may be a positive correlation (i.e.
religiosity & health), negative correlation (i.e.
TV watching & grades) , or no correlation (i.e.
study hours & height)
• Correlation does not imply causation
• Experiment = manipulation of one variable under
controlled conditions so that resulting changes in
another variable can be observed
– Detection of cause-and-effect relationships
– Example: effects of alcohol on aggression
• Independent variable (IV) = variable manipulated
(i.e. to receive or not receive alcohol)
• Dependent variable (DV) = variable affected by
manipulation (i.e. aggressive behavior)
• Quasi-experiments = compare two groups
that already exist in the population
Figure 2.17 Ethics in research