Question: John wanted to find the optimum conditions for growing peas. He planted pea seeds in 2 separate pots. He used the same amount and type of soil in each pot. He recorded daily care (amount of water and plant food) and results (plant length and number of leaves) after 2 weeks, as shown in the following chart. Did John do a good job of controlling the variables in his experiment? Explain why or why not.
Reference answer: No. John changed 2 variables at the same time (amount of water and amount of plant food) so John can not know which variables made a difference.

Student answer: No, Because John changed 2 variables not one. They are Pot A 25 milliliters of water 2 grams of food, Pot B 100 milliliters of water one gram of food.

Student answer: No, He did no have a controlled experiment.

Student answer: No, He did not do a good job because he changed 2 variables; water and food.

Student answer: Yes, It seems to be going fine well.

Student answer: Yes, Because he did not have Pot B the same as Pot A.

Student answer: Yes, Because the way he made the chart to stay organized.

Student answer: No, Because he changed 2 variables.

Student answer: No, Because he did not control his variables.

Student answer: No, Because he changed more than one variable; water and plant food.

Student answer: No, Because he changed 2 variables.

Student answer: No, Because in Pot A he used 75 milliliters then Pot B had 100 milliliters it is a big difference.

Student answer: No, He changed the water and the food and to have a controlled experiment you can only change one variable.

Student answer: No, He does not tell if the plant got sunlight or oxygen.

Student answer: Yes, Because he did the same thing a scientist would do by jotting down notes.

Student answer: Yes, Because it is neat, he recorded all plants, and he changed the watered and food to find the plants preferred environment.

Student answer: No, Because he changed too many variables in his experiment.

Student answer: No, Because the earth is sort of hard to read.

Student answer: No, Because for Pot B he put 100 milliliters this has too much water!

Student answer: No, Because too much water and less food does not make the plant feel good.

Student answer: No, I chose no because he needs to explain more in his experiment like what he measured.

Student answer: No, In that amount of weeks, it should of grew longer.

Student answer: No, Because if he wanted to control something he would of tried to control it.

Student answer: No, I think it is no because he did not show how much sunlight.

Student answer: No, because he could of put what happened after one week.

Student answer: No, He left a blank space on the chart.

Student answer: Yes, Because pot A's length is 8 centimeters and the number of leaves is 6.

Student answer: Yes, I think yes because he cares about his plants.

Student answer: Yes, Because it shows on the chart that he observed good.

Student answer: No, Because it should be 3 grams and 2 grams.

Student answer: Yes, Because he told us how many pots they were and everything he did.

Student answer: Yes, John did a great job because he has how many leaves grow and how tall it is and how much water and how much plant food.

Student answer: Yes, Because he used different amount of water and food and also watched both of them each day.

Student answer: No, He only used 2 kinds of pots. John needs more types of variables being changed.

Student answer: No, Because not only does he need more conditions but I still do not see the right amount of variables. The results do not really explain much.

Student answer: Yes, Because he organized his work good.

Student answer: Yes, There were different numbers.

Student answer: Yes, He had everything that he needed to take care of his plants.

Student answer: Yes, Because he tried to see if he could get the results.

Student answer: No, one gram of plant food should be alright for 100 milliliters of water.

Student answer: No, He did not give them the same food so that might have messed up his experiment.

Student answer: Yes, Because he did a good job of seeing what was the best way to grow it whether it is water or food.

Student answer: No, Because 2 things are different that may have caused a problem.

Student answer: No, Because he changed 2 things so you did not know if it is right or wrong.

Student answer: Yes, Because he put them in light and he also put water he also took the length of the plants.

Student answer: No, Because he did not control any variables.

Student answer: No, Because he did not feed the plant more if he did it will be a good job.

Student answer: Yes, Because he did not put that much water it still few about 8 centimeters.

Student answer: Yes, Because they both did not die and he found out his answer.

Student answer: Yes, Because the plants few food and you can see that the plants got good amount of water.

Student answer: Yes, Because he used separated pots and did either more or less water and different things.

Student answer: Yes, one is different than the other one.

Student answer: No, Because he could of kept water the same and the food so that is not controlling the variables good.

Student answer: No, Because he could say what color and where he left them.

Student answer: Yes, Because he kept track of them he made a chart so he is doing a good job.

Student answer: No, Because he did not put the same amount of water or food.

Student answer: Yes, Because the water amount is just right and from giving the plant food.

Student answer: Yes, Because he did different amounts of water a plant food to see which one would grow better.

Student answer: No, Because the reason Pot B did not do so well could be too much water, or no enough plant food, you could not know.

Student answer: Yes, Because he records his data and puts the same amount in one pot then does the same thing to another but another amount.

Student answer: Yes, John did a good job he put how much water, how much plant food, the length, the number of leaves. I like how he did his experiment.

Student answer: Yes, If he is trying to find the optimum condition he needs to test different stuff on each pot.

Student answer: Yes, Because John kept track of everything he was doing so he did not forget to do anything, and contained the whole project.

Student answer: Yes, Because he controlled everything he did to the plants.

Student answer: Yes, yes he wrote everything down that he did.

Student answer: Yes, He wanted to find out what the optimum conditions were so he gave one pea less water food to see what happens.

Student answer: Yes, because, he took care of his plants daily.

Student answer: Yes, Because, he did not use to much water and kill it, and I guess it was kind of tall, plus there was a lot of leaves.

Student answer: Yes, He recorded too much water, plant food, length and the number of leaves.

Student answer: Yes, He had everything he needed.

Student answer: No, I think he could have added the results after one week.

Student answer: Yes, He did a good job because he experimented 2 pots with plants after 2 weeks and recorded his observations.

Student answer: No, Because it seems that he got a mix up for the plants on the water.

Student answer: Yes, I think he did a good job because he tested the same plant in different pots and put different amounts of water and food. It was good that he tested 2 because if he only had one he would not have anything to compare it with and find if it is good or not.

Student answer: Yes, Yes because he used different amounts of water and food. He also used the same type of soil in both pots.

Student answer: Yes, I think he did well controlling his variable because by the chart it looks no variables happened.

Student answer: Yes, Yes because he examined what would be the best thing to do with a plant by experimenting with 2.

Student answer: No, He did not put a lot of information.

Student answer: No, Because he did not put the height of the plant.

Student answer: No, He did not do a good job because he did not say the height of the tallest plant.

Student answer: Yes, No explanation.

Student answer: Yes, Because at least all 2 plants have a plant and a leaf.

Student answer: No, Because in Pot A he did a good job but in Pot B he put 100 milliliters of water.

Student answer: Yes, Because they seemed to be tall and healthy plants.

Student answer: No, Because there is 2 different number of leaves.

Student answer: Yes, Results after week 2 are good.

Student answer: Yes, Because the plants grew well.

Student answer: Yes, Because he put more water in one but less food and the other one was vice versa but few more leaves and in length.

Student answer: No, Because he did not add the same amount of water or plant food.

Student answer: Yes, because he used one variable waters it was not all the same.

Student answer: No, no because in pot A he put 2 grams of plant food and in pot B one gram of plant food and he is only suppose to change water.

Student answer: Yes, yes because in pot B it was 100 and one gram and length it is 7 and for number it is only and it is good.

Student answer: Yes, because he wrote all his information.

Student answer: Yes, because on pot A he used 75 milliliters and got one more centimeters then pot B also he got more leaves on his plant in pot A.

Student answer: Yes, Yes because he put one more water one gram more on pot A and they grew more leaves and had the biggest length.

Student answer: Yes, yes because John put everything in the right order for pot A and B.

Student answer: Yes, Because recorded every detail.

Student answer: No, he add pot b to much of water.