In an experiment, the validation of the operational definition of the independent variable.

A true experiment that is conducted in a natural setting.

A major strength of experiments.

At this stage, participants may be questioned directly about their experience during the experiment.

This procedure is intended to reduce participants’ preoccupation with the true purpose of the experiment.

Aspects of an experiment that communicate unintentional cues to subjects about how they ought to act.

The epileptic seizure study was high in ________ because the experiment engaged subjects and had an impact on them.

May be strengthened through replication.

Because the laboratory situation was an uncommon experience for subjects in the epileptic seizure experiment, the study was low in ________.

Designed to reduce the impact of reactive measurement due to the experimenter.

Ensures that pre-experimental differences between experimental conditions are “neutralized” or distributed evenly.