Some Key Research Terms
Experiment: the research strategy that tests the behavioral effects of one or more variables (by manipulating an independent variable and measuring the effect on some dependent variable)
Dependent Variable: the variable being measured in an experiment (to test the outcome of some manipulation of an independent variable)
Independent Variable: the variable being manipulated in an experiment (in order to study its effect)
Double-blind: the research procedure in which neither the participant nor the experimenter knows which condition the participant is in (to control for the placebo effect)
Control Condition: the "treatment-absent" condition in an experiment (used as a comparison for evaluating the effect of the treatment)
Experimental Condition: the "treatment-present" condition in an experiment
Random Assignment: selecting subjects by chance for different conditions in an experiment (to control other relevant factors)
Placebo: a false or ineffective treatment administered as if it were the real treatment; any change in behavior would be due to the subject's expectations (the placebo effect) rather than to the treatment
Every field of science has its own technical vocabulary, and psychological research is no exception. Here are some essential research terms. Experiments explore cause and effect by manipulating an independent variable, measuring the dependent variable, and controlling all other variables. An experiment manipulates the independent variable by setting up at least two different conditions: an experimental condition and a comparison or control condition. Random assignment of subjects to conditions works to equate the conditions before any treatment effects. The subjects' expectations about the treatment may influence their behavior, so the control condition often includes a placebo or sham treatment. The double-blind procedure ensures that subjects do not know which condition they are in, and this controls for a possible placebo effect.