What is the independent variable and control group?

In lab we experimented on pill bugs. A chamber was created by connecting two petri dishes allowing the pill bugs to move from each dish. The hypothesis was that the number of pill bugs in an area is dependent on wetness- the more wet the dish the more pill bugs. Therefore one dish was wet and one dry. Five bugs were initially placed in each dish. What is the independent variable and the control group of the experiment. I thought the wetness would be the independent variable and the 5 pill bugs in that started in the dry dish to be the control group. However the teacher marked these answers as wrong. Does anyone know the right answer?|||The wetness of the dish is the independent variable. The independent variable is the one that you change on purpose. Your teacher is WRONG on that one.





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As for the control group, in my opinion you didn't have one. A control group for this experiment would have been 10 pill bugs 5 in each two dry interconnected petri dishes.





The experiment is poorly designed without this control and without doing several repetitions. If I really wanted to study this I would start out with at least 10 pairs of chambers.10 that were both dry, and 10 that were one wet and one dry.





That being said, if I had to call one of the groups a control group I would say it was the group that was already in the wet petri dish. We expect them to stay put and the others to move.





All and all I would say this is a very confusing experiment designed by a teacher that has no background in research.|||" my teacher said that time was the independent variable and that all the pill bugs were the control group"





I challenge your teacher to explain how time is an independent variable. We have absolutely no control over time. It's an "independent variable" in every experiment.

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|||the independent variable is what you change,


the dependent variable is what you measure, and


the control is the smallest or least level of your independent variable