Variables help pleasee

[janhavi.shinde]

Can someone please differentiate USING EXAMPLES, controlled, control and constant variables for me please everything online is contradicting itself


Mod edit: changed title from all-caps

[Bri MT]

The study design asks you to "identify independent, dependent and controlled variables"; I'm not sure why you're trying to distinguish between controlled, control and constant variables - these terms tend to be used synonymously.


Let's say you are interesting in measuring the impact of enzyme concentration on reaction rate.

Your IV would be enzyme concentration and your DV would be reaction rate

Ideally, everything else would be controlled and kept constant, but often it's impractical to control every single other possible thing so you identify what's likely to have an impact on your experiment and control for that.

For example, in this experiment temperature is likely to have significant impact so you may decide to have temperature as a controlled variable.

I'm not sure that this is the answer you were looking for but I hope it helps

[InnererSchweinehund]

Can someone please differentiate USING EXAMPLES, controlled, control and constant variables for me please everything online is contradicting itself


Mod edit: changed title from all-caps

Hi there!
 
Controlled and constant variables are the same thing - the things you keep the same throughout the experiment. With the example of Pasteur's experiment, controlled variables would include amount of broth used, type of flask used, temperature of the room, exposure of the flasks to sunlight etc.

The control is Pasteur's experiment is the flask (with broth) that is sealed. The control variable demonstrates what would happen if nothing is done to it, so you can then compare the results of your independent variables trials to it.
Another good (and easy) example of a control is when you are 'modelling' Koch's experiment and looking at testing water or food samples.
During this experiment, you would leave an agar plate closed (never open it), seal it and incubate it. If your agar is pure, then nothing would happen. This is a control because nothing is done to it, so you compare the growth of bacteria / other microorganisms (which should be 0 on the control plate), to the other plates, that may have been streaked with a liquid or food product for example. This demonstrates that it's not the agar causing this microbial growth, but rather the substance you used on it.

Hope this helps!