Otherwise, you have no idea which variable change affected the result. Did the plant die for lack of light? Or because you also cut off its air supply? Or put it in a closet full of mothballs? Or put it in reach of the cat who tore it up? Or put it out of sight so you forgot to water it?
February 21st, 2010 at 7:37 pm
You test one variable at a time in order to verify what caused a change in your experiment.
Example:
I add a blue liquid to a yellow liquid. The result is green. Now say I add red at the same time. Different result that can’t be attributed to either added liquid. It also allows you to detail your process so that others may duplicate your findings.
References :
February 21st, 2010 at 8:01 pm
Otherwise, you have no idea which variable change affected the result. Did the plant die for lack of light? Or because you also cut off its air supply? Or put it in a closet full of mothballs? Or put it in reach of the cat who tore it up? Or put it out of sight so you forgot to water it?
References :
February 21st, 2010 at 8:36 pm
So that you would know what caused that particular change in your experiment.
References :