Difference between confounding and exraneous variables

Zziggi

Can anyone explain this one to me - please?

Tigersilly

Extraneous variables
An extraneous variable is something from the outside that creeps into an experiment and gives rise to an alternative explanation for your results.

Experiments are all about establishing 'cause and effect' between an independent variable and a dependent variable. Extraneous variables that pollute cause and effect conclusions in psychology are to be avoided.

Extraneous variables are of two kinds, random variables, and confounding variables.

• Random extraneous variables just happen. You the experimenter have no control over them. They cannot be anticipated or controlled. Examples of random variables that could give rise to another explanation for your results would be in a laboratory experiment when a radiator starts making a funny noise, and distracts participants who are in the middle of doing something. Another would be in a field experiment when it starts chucking it down with rain!
• Confounding variables are of three kinds. Those attributed to the experimenter; those attributed to the situation; and those attributed to the participant. For more on situational, experimenter, and participant variables see 'Approaches & Methods' Chapter 8 'The Experimental Method.' You will discover more on these confounding extraneous variables and how they can be controlled if anticipated by the researcher.[SIZE=+1] [/SIZE]

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