I don't understand the Point of a Control - Why are they used? Watch

ΘTheta
Badges: 10
Rep:
?
#1
Report Thread starter 4 years ago
#1
Why do Scientists use controls guys? Thanks! =)
0
reply
Lethorio
Badges: 11
Rep:
?
#2
Report 4 years ago
#2
Without a control, you'd have nothing to test whatever you're experimenting against. They're used for comparison.
0
reply
tomtjl
Badges: 14
Rep:
?
#3
Report 4 years ago
#3
They're used to prove that the independent variable is what is actually causing the change. Otherwise, you could argue that something else is causing the change in the dependent variable.
0
reply
ΘTheta
Badges: 10
Rep:
?
#4
Report Thread starter 4 years ago
#4
(Original post by tomtjl)
They're used to prove that the independent variable is what is actually causing the change. Otherwise, you could argue that something else is causing the change in the dependent variable.
Hello there, thanks for the response.
So if for example you were testing the effect of different concentrations/varieties of fertilizers on plant growth, by measuring its height, you would leave a plant with no fertilizers (exposed to the environmental conditions as the other fertilizers), and so this is the control. Hence you could compare the control plant with the experimental plants?

Would it also mean that the increase in plant heights were due to the fertilizers?
0
reply
tomtjl
Badges: 14
Rep:
?
#5
Report 4 years ago
#5
(Original post by ΘTheta)
Hello there, thanks for the response.
So if for example you were testing the effect of different concentrations/varieties of fertilizers on plant growth, by measuring its height, you would leave a plant with no fertilizers (exposed to the environmental conditions as the other fertilizers), and so this is the control. Hence you could compare the control plant with the experimental plants?

Would it also mean that the increase in plant heights were due to the fertilizers?
Yes. The control group must be exactly the same as all the other groups, except for the independent variable. So in this case the control group would be kept exactly the same except it would have no fertilizers. Then, when the plant grows to a lower height, you can definitively say that the increase in height is due to the fertilizer and not some other factor.

Hope I helped!
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Edge Hill University
    Undergraduate and Postgraduate - Campus Tour Undergraduate
    Mon, 18 Feb '19
  • University of the Arts London
    MA Innovation Management Open Day Postgraduate
    Mon, 18 Feb '19
  • University of Roehampton
    Department of Media, Culture and Language; School of Education; Business School Undergraduate
    Tue, 19 Feb '19

Do you give blood?

Yes (61)
8.65%
I used to but I don't now (17)
2.41%
No, but I want to start (265)
37.59%
No, I am unable to (167)
23.69%
No, I chose not to (195)
27.66%

Watched Threads

View All