Science Buddies: "Ask an Expert"

Hi
I am doing a science fair project on topic diy art robot, I am creating 2 robots with different type of body, everything is same only body is different. One out of a plastic cup and one out of a soda can. My question is what should I write in variables. I think variables will be
Dependent variable: movement
Independent variable: robot body
Constant variable: circuit
Am I correct, are these my variable or I am wrong. Any suggestion about variables if mine are not correct.
Thank you

Hello samydeem,

The general idea of your variables is correct. However, you should specify what you mean by "movement" for your dependent variable. Do you mean the speed of the robot's movement, or the distance the robot moved? Also, since the constant variables are the factors or conditions that do not change during your experiment, you can probably list several more besides "circuit." For example, you can state that your constant variables are the voltage, current, resistance, etc. of the circuit; you can most likely list even more that are not related to the circuit.

Basically, the dependent variable is what changes in response to a change in something else (the independent variable) in your experiment. In other words, the value of the dependent variable (the speed of the robot, for example) depends on the independent variable (the type of robot body use, for example).

thanx for replying cvionis. Really appreciate.
So can i write power supply instead of circuit as constant variable.

Hi samydeem,

Cvionis has given you a good explanation of dependent, independent and control (constant) variables.

The Science Buddies project guide also has a good section on variables including some useful examples:

https://www.sciencebuddies.org/science- ... ience-fair

Hope this helps!

Hello samydeem,

Yes, it would be a much better idea to replace "circuit" with "power supply," since doing so makes this constant variable much more specific/clear.

Please let me know if you need any help on how to find that or anything else.