My science final. Making my own lab. (help)

Ok so my science final is to make our own lab involving those little sponge capsules that turn into animals when put in water. I understand that hotter water will dissolve the capsule faster because the molecules are moving much faster and are hitting the solute more. Each student gets 4 capsules to use, so I will have room temperature water, boiling, and ice water and the water temperature recommended on the back of the capsules box (50-60 c. which is 122-140 f) . My question is which one is my control? I have figured that it would either be the room temperature water or the recommended water, but which and why?

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NachoMahma10 years ago
. From what little I recall of Statistics, you don't have a control group. A control group is not subjected to the experimental variable(s) - water temp in your case. I suppose you could call the room temp sample/group the control, but I don't think it holds up to any of the definitions I found on the Web. But I'm no Statistician. ;)
I agree with the others that the teacher would expect the recc. temp as the control. BTW, not knowing what grade level you are, is he having you graph the points? you could do a simple linear regression from any of he two points and then plot the other two points, if they fall along the line you can then, reasonably, state that the correlation between time and temp is linear.
I would do that, but the assignment is to write up a hypothesis and procedure, and then perform the lab in front of her, so I wouldn't be able to have any of the results until post lab.
The capsules are not too expensive - you could go out and buy more, preform the experiment at home, so that when it comes time for the real deal, you can know what to expect.
Bran10 years ago
For your project, the recommended temperature would be the control, as it is standard. Personally, I would've went about it differently. Instead of having different temperatures of water, I would have used the same temperature, but different substances, like vinegar, ammonia, alcohol, etc.
I would say your control would be the recommended temperature, because you aren't changing anything from the norm. Room temperature would be an experiment.