Observation
The trash smells.
Explanation
Decaying biological material causes the trash to smell.
Test (independent variable)
Add food scraps to one trash can along with other materials, such as plastic, cardboard, paper, and tin. To a second trash can, add only non-food materials, such as plastic, cardboard, paper, and tin. Observe the smell of each trash can over a few days.
Prediction (dependent variable)
The trash can with food scraps added to it will smell more than the trash can with non-food materials.
Hypothesis
If decaying matter causes the trash to smell, then removing food scraps from the trash will decrease the odor that it produces.
Is there a control group and why?
please help
food scraps is the independent variable
odor (stink/smell) is the dependent variable
the control is the can without scraps
I know it has a control group I just don't know how to explain why
thank you
why is the can of scraps the control group?
without*
the trash without the food is the control because nothing is being done to it. you are testing to see if the food makes the trash smell.
Yes, in this experiment, the trash can with only non-food materials (plastic, cardboard, paper, and tin) serves as the control group. The control group is used as a baseline for comparison to the experimental group (trash can with food scraps added).
Having a control group is important because it allows us to isolate the effect of the independent variable (adding food scraps) on the dependent variable (smell of the trash). By comparing the odor of the trash can with food scraps to the control group, we can determine if the food scraps are indeed causing the increased smell.