In this science fair project, what will or can be my control?

Question

Getting water from the air has great importance insurvival if you are ever stranded in the woods. Take alarge black plastic garbage bag and cut one side open soyou can open it up to make one large flat piece. It willprobably be about three or four feet square. Dig a holeone foot deep and almost as wide as the spread out plasticbag. Put a shallow cup or bowl at the center of the hole.Stake each corner of the bag to cover the hole. Put apebble or small rock on the top of the bag to depress thebag’s center slightly, being sure not to let it sag deepenough to touch the container underneath. Using twothermometers, measure the temperature in the hole underthe bag and the outside air temperature. Condensation will form on the underside of the bag and will drip down intothe container if the outside air heats up and the airinside the hole remains cooler.

Answer 1

You have the answer in your question!

A control is used to show that it is what change you made that caused your result. You state "Condensation will form... IF THE OUTSIDE AIR HEATS UP AND THE AIR INSIDE THE HOLE REMAINS COOLER." So there's your experiment (change the temperature) and your control (keep the temperature the same). Just measure how much/if you get condensation by varying the temp!