Download Psychological Research Methods: Experimentation, Correlation, and Description - Prof. Dori and more Study notes Psychology in PDF only on Docsity! Methods of Psychological Research of • Experimentation • Correlational Studies • Descriptive Studies – Observation – Case Studies – Surveys Experimentation • Steps in designing an experiment – formulate a hypothesis – determine the variables of interest – identify groups to compare – select and assign subjects Identify groups to compare You need to compare students who are praised for contributing in class with those who are not praised • experimental group - subjects who are exposed to the independent variable • control group - subjects who are not exposed to the independent variable • experimental group - the subjects who are praised for contributing in class • control group -the subjects who are not praised for contributing in class everything except the independent variable should be the same for both groups: • instructor • class time • etc Select and assign subjects • How you select your subjects and assign them to groups can affect the outcome of your experiment • Random assignment helps ensure the groups will be comparable Subjects in the control group might be given a placebo - a substance that causes no physiological effect, such as a sugar pill • An industrial psychologist believes that cooling the room temperature may have an impact on the productivity of workers on an assembly line hypothesis independent variable dependent variable experimental group control group Hawthorne Effect - people sometimes change their behavior because of the novelty of the situation or because they know they are being observed. Research in which this effect was first noted was conducted at the General Electric Hawthorne Plant Strength
1.00
-76-.99
91-.75
-26-.50
.01-.25
.00
Perfect relationship; the two
factors always occur together
Very strong relationship; the two
factors occur together very often
Strong relationship; the two
factors occur together frequently
Moderate relationship; the two
factors occur together
occasionally
Weak relationship; the two
factors seldom occur together
No relationship; the two factors
never occur together
Correlations are rarely perfect
Poe
ee
A positive correlation occurs when high values for one variable are associated with high values for another variable An example might be education level and annual income Direction Correlation is not causation !!! When two events are correlated, it does not mean that one event causes the other Two events can co-occur by chance, or because they are both caused by some third variable (third variable problem) As the temperature drops, people in the Washington area go to more parties. Does cold weather cause people to go to parties? Do parties lower the temperature? Come up with your own examples: Positive correlation Negative correlation Co-occurrence (with a third variable) Jane Goodall at the Gombe Stream Reserve Dian Fossey, Rwanda • Observation may also be conducted in a laboratory, where the experimenter has control over the environment In participant observation the researcher becomes part of the observed group Leon Festinger, 1950s, Doomsday Cult Surveys and Interviews • Surveys include all sorts of questionnaires and interviews • They allow researchers to survey a small sample and make conclusions about whole populations • Some examples of surveys you might be familiar with are focus groups on products, Nielsen ratings for tv, and the US census • people sometimes answer the way they think they “should” or to make themselves look better (social desirability effect) • people who respond to surveys might not be representative of the entire population (volunteer bias) Some problems with survey research:
