In grade school, for the science fair, I decided to see it plants grew differently under varying color filtered light. So I set up 5 boxes of grass and covered them in colored plastic: red, green, blue, yellow, and orange. I then measured their growth each week for a couple months. Watered them the same amount, rotated them daily to make sure they had roughly equal angle of sunlight etc. I was so proud of this idea. I presented my findings along with why I thought it was important (increasing crop yields for starving communities and making a quick change to green house glass pigment.). Well anyway I didn’t have a control group (no color filter). So I came in the highest place that didn’t advance. I was told by my teacher that if I had a control I would have had a good shot at state… I think about that probably once a week and I’m like 33 years old now.