control and data for science fair?

[kenzis-mommy]

My kindergartener is in her first science fair. We are doing "transpiration" and our demonstration uses food coloring in water and white carnations to show what happens when plants drink. She grasps the process and our flowers are cooperating and changing colors as they should. However, I am stumbling on what the "control" is for this experiment? Also, any suggestions for the data we should measure? (should we measure water in the cups? should we measure patterns in the color changes?)

[staryl13]

Hi!
So the control for this experiment would be growing the carnations in pure (clear) water and showing that there is no color change in the flowers. In terms of measuring the data, I think that the best would be to create a color ranking (for example, 1 being white and 5 being red and all the shades in between from 2-4). I also think that measuring how much water is in the cups before and after the experiment would also be a great idea as well. Sounds like a great project and best of luck!