Science Buddies: "Ask an Expert"

Hi,

For my science project, I am testing the melting times of different types of chocolate. I put them in the shade and then in the sun. I know the types of chocolate are an independent variable. But, are the sun and shade also independent variables? Or are they controlled because they are the same for all the chocolates at the same time?

Thanks for your help!

Hello,

Great experiment! You're correct; the different chocolate types are independent variables because they are manipulated to observe any effects on melting times. However, the sun and shade can be either independent or control variables. This depends on how you are using these variables. They will be a controlled variable if you ensure the exposure between all chocolate types is consistent. They are an independent variable if you vary the exposure to study its effect.

I hope this helps!