How does a scientist know HOW to change the independent variable?

Question

any help would be app. thank you

Answer 1

The timer goes off and the liquid turns red

Answer 2

You will usually have some knowledge over the range that you want to change this variable.  It also will have to do with the range over which you can measure the dependent variable.

Say I'm investigating degradation of a pollutant X to metabolite Y by bacteria in a sewage treatment plant.  I'll have some knowledge, by lab measurements, of what range of concentration pollutant X might appear in the wastewater.  So  I'll pick concentrations that represent that, and run my experiment on those concentrations, and measure how much Y was made.

I might have a lower limit to the amount of Y I can detect.  So it would make no sense to pick concentrations of X so low that even if there was conversion, I could not detect it.

Another reason might be that under the measured range of concentration of X, I get no conversion to Y.  So I might try using a much higher concentration of X, just to see if I get conversion then.  If I do, then I know that at the range of X that my process gets, it does not change it to Y.

DK

Answer 3

The question is that independent variable is the variable scientists want to change. If he or she doesn't know how to change it, he or she can't do the research. So we have to know how to change independent variable before we do the research. You can look it up from the Internet or ask someone else for help.