The Experimental Method

The Experimental Method:
(Independent & Dependent Variables)

Why is this Important?

As a psychologist, you will read much research and hear many reports. It is crucial that one can distinguish between experimental and non-experimental research.

The Big Points:

Experimental and nonexperimental research are distinguished by the degree of control that the researcher has over the subjects and conditions in the study.
You must distinguish between manipulation and assignment versus observation.
An experiment is an investigation in which some variable is manipulated
You have to know what a variable is:

A variable is an aspect of the testing condition that can change or take on different characteristics with changes in conditions

Learn This: You have to know the difference between an Independent and Dependent Variable.

Fancy Definitions and Examples:
IV - Independent Variable:

The Condition or Factor Manipulated or Selected by the Experimenter to Determine Its Effect on the Subject

Examples of IVs:

Differential Dosage of a Drug Given Control Fever

Different Kinds of Psychotherapies for Depression

Various Amounts of Sugar Used to Reinforce A Rat For Running a Maze

DV - Dependent Variable:

A measure taken from the subject that reflects the effects of the independent variable (IV)

Examples of DVs that Correspond to Our IVs:

Differential Dosage…Measure Body Temperature

Psychotherapies…Given them a test like the Beck Depression Inventory

Sugar…Number of Trials it Takes the Rat to Learn the Maze

The Nutshell - you change the IV &

measure its effect on the DV.

psychimages/Images that Will
Help

Other Things You Should Know About Variables