System of gathering data so that bias and error in measurement are reduced.

• hypothesis

• scientific method

• representative sample

• case study

Tentative explanation of a phenomenon based on observations.

• experiment

• correlation

• hypothesis

• case study

Study of one individual in great detail.

• case study

• correlation

• representative sample

• experiment

Randomly selected sample of subjects from a larger population of subjects.

• case study

• hypothesis

• independent variable

• representative sample

A measure of the relationship between two variables.

• scientific method

• experiment

• correlation

• dependent variable

A deliberate manipulation of a variable to if corresponding changes in behavior result, allowing the determination of cause-and-effect relationships.

• experiment

• operational definition

• independent variable

• dependent variable

Definition of a variable of interest that allows it to be measured.

• scientific method

• hypothesis

• operational definition

• experiment

Variable in an experiment that is manipulated by the experimenter.

• independent variable

• dependent variable

• experiment

• correlation

Variable in an experiment that represents the measurable response or behavior of the subjects in the experiment.

• independent variable

• dependent variable

• operational definition

• experiment