ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Psychology => Topic started by: izzykose on May 23, 2011, 05:39:20 pm

Title: Extraneous and Confounding Variables
Post by: izzykose on May 23, 2011, 05:39:20 pm
These are my notes explaining each variable. (I have experienced confusion as to what the difference is between them..)

Extraneous Variables

An extraneous variable is a variable other than the IV which CAN or MAY have the POTENTIAL to have an effect on the participant performance on the DV, which therefore effects the results of an experiment in an unwanted way. At the outset of an experiment, extraneous variables are identified and if these are relevant to the experiment, or have the potential to cause a change in the DV, they may be controlled for. Thus, an extraneous variable for an experiment could include the temperature in the room during the experiment. It is an extraneous variable as it may or may not have had an effect on the results of the experiment and this effect is not measureable. Another extraneous variable may include the role of proactive and retroactive interference in causing a change to a participant’s ability to recall the numbers in a series of lists such as in a digit-span test. This is extraneous as it may or may not have affected the results, however this effect is not measureable and must be controlled for in future experiments.

Confounding Variables

A confounding variable is a variable other than the IV, which has HAD an effect on the participant performance on the DV, which therefore affects the results of an experiment in an unwanted way. A confounding variable makes it impossible to determine whether or not the IV produced the change observed or caused participants to act or respond in a certain way; as this affect could have been caused by the confounding variable. A confounding variable is one which produces a change in the DV which is consistent with what was predicted in the hypothesis and thus it is confusing as to which variable actually contributed to this change.


So basically.. are these explanations correct and in a potential research methods question in Section C, would we have to identify confounding variables... because, as i see it, it would be impossible to tell whether a confounding variable was present, UNLESS there was a second experiment done which had conflicting results or another experiment was done which produced the same results as hypothesised in the first experiments, while testing an IV that was not tested in the first experiment..

Follow me... im still confused..
Title: Re: Extraneous and Confounding Variables
Post by: Camo on May 23, 2011, 06:18:07 pm
I don't think you can determine a confounding variable on an exam question without research to support there was a confounding variable. Extraneous however you would be able to I believe.
Title: Re: Extraneous and Confounding Variables
Post by: iNerd on May 23, 2011, 06:24:17 pm
I don't think you can determine a confounding variable on an exam question without research to support there was a confounding variable. Extraneous however you would be able to I believe.
This.

And dude your notes are huge.

293 words? I have 104 words on EV + CV.
Title: Re: Extraneous and Confounding Variables
Post by: izzykose on May 23, 2011, 06:43:38 pm
Yeah i didnt think so..

but am i right in my definitions of both?

That extraneous is a variable that may or may not have effected the results and was not controlled for.

Confounding is a variable that had an effect on the results, and thus is confused with the IV. Confounding variables are variables other than the IV that produce a change consistent with the hypothesis and thus it is impossible to determine whether or not the IV was the reason for that change..

Also in the practice exam research methods question.. is it appropriate to talk about extraneous variables or criticisms of the research im not sure that falls under the "your answer should include" dot points?
Title: Re: Extraneous and Confounding Variables
Post by: Camo on May 23, 2011, 06:44:12 pm
Thanks ATAR, and thanks izzykose, now I know what a confounding variable is to. :)
Title: Re: Extraneous and Confounding Variables
Post by: iNerd on May 23, 2011, 06:45:19 pm
Stop being so wordy....

EV - may effect.

CV - does effect.

I don't know to make it any clearer.
Title: Re: Extraneous and Confounding Variables
Post by: HasibA on February 20, 2016, 11:11:32 pm
Hi guys,

How can you tell if a variable is confounding or not in an experiment in the exam (for example)?

Also, aren't extraneous variables and potentially confounding variables pretty much the same thing (because they're potential, they may or may not have an effect, like for extraneous variables)?
this thread is like 5 years old- try not to bump it unnecessarily.. :) if you have questions, go on the Psych Question thread!
Title: Re: Extraneous and Confounding Variables
Post by: scout on February 20, 2016, 11:32:33 pm
this thread is like 5 years old- try not to bump it unnecessarily.. :) if you have questions, go on the Psych Question thread!

Got it  :) :)