Case Study
A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.
Confounding Variable
A factor other than the factor that is being studied that may affect the study’s results.
Control Condition
The group not being exposed to the treatment, compared with the results of the group being exposed to the treatment.
Correlation
A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.
Correlation Coefficient
A statistical index of the relationship between two things.
Dependent Variable
The outcome of an experiment that is measured.
Double Blind
An experimental procedure in which both the research participants and the staff are ignorant about whether the research participants have received the treatment or a placebo.
Experiment
A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process.
Hindsight Bias
The tendency to believe one would have foreseen an outcome after learning it.
Hypothesis
A testable prediction.
Independent Variable
The factor in an experiment that is manipulated.
Mean
The average of a distribution.
Median
The middle score in a distribution.
Mode
The most frequently occurring number in a data set.
Naturalistic Observation
A descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.
Operational Definition
A carefully worded statement of the exact procedures used in a research study.
Overconfidence
The tendency to be more confident than correct.
Placebo Effect
Experimental results caused by expectations alone, in which the recipient assumes they have been given an active agent.
Population
All those in a group being studied, from which samples may be drawn.
Random Assignment
Assigning participants to control and experimental groups by chance.
Random Sample
A sample that fairly represents a population because each member has an equal chance of inclusion.
Range
The difference between the highest and lowest score in a distribution.
Replication
Repeating a research study,