Page 1 of 1

### What is my control group

Posted: Sat Mar 25, 2017 10:31 am
We are doing an experiment to see how many numbers a person can remember. We start with 1 and go all the way up to 10 numbers. We then will analyze to see what is the most common amount of numbers most people can remember. Our teacher has said we need to have an experimental variable, an experimental group and a control group. I think the experimental variable is changing the amount of numbers each time, the experimental group would be the people we are testing, but what would be the control group?? If it was a control variable, it would be that each person receives the same numbers, but if I need a control group what would that be??? I can not figure this out...please help!!

### Re: What is my control group

Posted: Mon Mar 27, 2017 6:58 pm
Hello, and welcome to Science Buddies!

There are different types of investigations. Your teacher is referencing an experimental investigation, which investigates a cause and effect relationship. For example, if you wanted to conduct your memory test with some subjects resting in a chair while others running in place, you would be examining the effect physical activity has on memory; and the resting group would be your control group.

However, if you are going to test everyone the same and just change the numbers, then you are conducting a comparative investigation; and no control group is required. You will still have independent and dependent variables.

You can read more here about the difference between the two and more details of definitions. Take a look and write back if you have further questions. Good luck!
https://www.texasgateway.org/node/3942
https://1.cdn.edl.io/J2J9xnmHlMIYY0OA0Q5v1SKVm6VdTvxbMcyMk7tEcssNW4by.pdf

### Re: What is my control group

Posted: Mon Mar 27, 2017 7:28 pm
Hello rvignau,

The previous expert has given you excellent advice and a very good reference. It occurs to me that you could also think of this experimental design as one where each person (subject) is their own control, since you will be comparing the results for each of your conditions for person A to that person's results. Looked at this way, you now can explain to your teacher that you do, indeed, have controls!

Best of luck!