Controlling Extraneous Variables

When conducting experiments, researchers aim to create treatment conditions that clearly reveal the effects of ______ variables.

The three general techniques for controlling for physical variables include elimination, constancy of conditions, and ______.

To ensure an extraneous variable doesn't impact the experiment, sometimes we eliminate it. If this is not possible, we can apply ______ of conditions.

Constancy of conditions involves keeping all aspects of the treatment conditions as nearly ______ as possible.

If neither elimination nor constancy can be used, the third technique controlling physical variables involves ______.

A potential confound occurs when something in the experiment changes ______ along with the independent variable.

When we want our experiments to be internally valid, only the ______ variable should change systematically from one condition to another.

Physical variables are aspects of the testing conditions that need to be ______ to minimize their impact on the results of an experiment.

To avoid potential confounds, researchers may control some variables that would not have affected the results anyway, but it is better to use the ______ than to have regrets later.

In balancing, researchers must distribute the effects of an ______ variable across different treatment conditions of the experiment.

If one group had lunch but the other didn't, the experimenter will have a hard time making a strong case for the effects of the ______ variable.

If we cannot eliminate extraneous physical variables or keep them constant throughout an experiment, we can still make sure that they do not ______ the results.

Variables that also threaten an experiment's external validity by reducing the ______ of the findings can be physical, social, personality, and context.

Factors such as the weather, the lighting, and the paint on the walls are simply there; we often cannot eliminate them, so we apply ______ of conditions.

By using control techniques, we increase the chances of an ______ valid experiment.

To make sure that any extraneous variables do not affect an experiment, we can just take it out--we ______ it.

We also try to keep the ______ of the testing procedures the same.

In balancing, we are ______ the effects of extraneous physical variables across treatment conditions of the experiment

The A group may do better if it is tested in the same sunny room in which the B group is tested. The key to controlling variables that cannot be eliminated or held constant is the third technique for physical variables- ______.

Emily's experiment was in real trouble because she ran all subjects getting treatment A on a Thursday and all of those getting treatment B on a ______.