Confounding/Extraneous Variables

[Insomniac]

What's the difference between confounding and extraneous variables? I know confounding variables are a type of extraneous variable but how else are they different and could you give me an example?

Thanks!

[brenden]

Confounding variables essentially act as another Independent Variable (the one the whole study relies on). For example, say we wanted to test the intelligence of people from differing socioeconomic areas. From Frankston we get a bunch of 12 year olds and from the Melbourne CBD we get a bunch of 20 year olds. So the socioeconomic status is intended to be the IV, however, the age acts as another independent variable which effectively ruins the study. Having a confounding variable makes it impossible to determine whether or not the DV was prompted by the IV or the CV. (In the above situation it's very blatant that age is the factor, however I wanted to get my point across. With a less extreme study we wouldn't be able to tell which one was the one causing the DV).
An extraneous variable can cause a change in the DV and affect the results of the experiment in an unwanted way, however they are generally acknowledged and counteracted prior to the study commencing, and  thus they don't turn into a CV.

[dzzhao]

Every time someone asks this question, I always see someone else give a fat long paragraph like above trying to help explain what the difference is when it really can be put into simple terms in a simple way without a massive example

Extraneous - other variables in the experiment that can have an affect on the DV
Confounding - Uncontrolled extraneous variables that have a systematic effect on the DV


done

[brenden]

What's the difference between confounding and extraneous variables? I know confounding variables are a type of extraneous variable but how else are they different and could you give me an example?

[dzzhao]

What's the difference between confounding and extraneous variables? I know confounding variables are a type of extraneous variable but how else are they different and could you give me an example?

I know he asked for one and you did the right thing, but I'm sure he asked it to try and get a better understanding. A good understanding can actually be put into more simple terms if just said what's above

[brenden]

Yeah fair point actually.

[Insomniac]

Confounding variables essentially act as another Independent Variable (the one the whole study relies on). For example, say we wanted to test the intelligence of people from differing socioeconomic areas. From Frankston we get a bunch of 12 year olds and from the Melbourne CBD we get a bunch of 20 year olds. So the socioeconomic status is intended to be the IV, however, the age acts as another independent variable which effectively ruins the study. Having a confounding variable makes it impossible to determine whether or not the DV was prompted by the IV or the CV. (In the above situation it's very blatant that age is the factor, however I wanted to get my point across. With a less extreme study we wouldn't be able to tell which one was the one causing the DV).

An extraneous variable can cause a change in the DV and affect the results of the experiment in an unwanted way, however they are generally acknowledged and counteracted prior to the study commencing, and  thus they don't turn into a CV.

Thanks!

[brenden]

You're welcome