| causal relationship | A relationship in which changes in the value of one variable cause changes in the value of another.
|
 |
|
|
| confounding | Two variables that vary together in such a way that the effects of one cannot be separated from the effects of the other.
|
|
|
|
| control group | A group of subjects in an experiment that does not receive the experimental treatment. The data from the control group are used as a baseline against which data from the experimental group are compared.
|
|
|
|
| correlational relationship | A relationship in which the value of one variable changes systematically with the value of a second variable.
|
|
|
|
| correlational research | Research in which no independent variables are manipulated. Instead, two or more dependent variables are measured to identify possible correlational relationships.
|
|
|
|
| demonstration | A nonexperimental technique in which some phenomenon is demonstrated. No control group is used.
|
|
|
|
| dependent variable | The variable measured in a study. Its value is determined by the behavior of the subject and may depend on the value of the independent variable.
|
|
|
|
| directionality problem | Based on correlational research, you cannot always specify whether changes in variable A cause changes in variable B, or vice versa.
|
|
|
|
| experimental group | A group of subjects in an experiment that receives a nonzero level of the independent variable.
|
|
|
|
| experimental research | Research in which -independent variables are manipulated and behavior is measured while extraneous variables are controlled.
|
|
|
|
| external validity | The extent to which the results of a study extend beyond the limited sample used in the study.
|
|
|
|
| extraneous variable | Any variable that is not systematically manipulated in an experiment but that still may affect the behavior being observed.
|
|
|
|
| independent variable | The variable that is manipulated in an experiment. Its value is determined by the experimenter, not by the subject.
|
|
|
|
| internal validity | The extent to which a study evaluates the intended hypotheses.
|
|
|
|
| Random assignment | The process assigning subjects to experimental treatments randomly.
|
|
|
|
| simulation | A laboratory research technique in which you attempt to re-create as closely as possible a real-world phenomenon.
|
|
|
|
| third-variable problem | A problem that interferes with drawing causal inferences from correlational results. A third, unmeasured variable affects both measured variables, causing the latter to appear correlated even though neither variable influences the other.
|
|
|
|
| treatment | A level of an independent variable applied during an experiment. In multifactor designs, a specific combination of the levels of each factor.
|