Science Buddies: "Ask an Expert"

My son is doing a science project on how chicks breathe through the shell. I am confused to the variables: independent, dependent, and controls.

I think independent might be the age of the egg, dependent might be the amount of food coloring inside the shell after soaking, and controls might be the color of food dye and how much food dye is used?

Any help in explaining what the different variables mean and how to apply to this project would be appreciated.

angeliquekim wrote:My son is doing a science project on how chicks breathe through the shell. I am confused to the variables: independent, dependent, and controls.

I think independent might be the age of the egg, dependent might be the amount of food coloring inside the shell after soaking, and controls might be the color of food dye and how much food dye is used?

Any help in explaining what the different variables mean and how to apply to this project would be appreciated.

Dear Ms. Kim,

That's awesome that your son has decided to do this project: https://www.sciencebuddies.org/science- ... p046.shtml (How Does a Chick Breathe Inside Its Shell?)

If your son is doing one of the variations of this project, in which he compares fresh vs. aged eggs, then his scientific question would most likely be "How does the age of the egg affect the transfer of oxygen in the egg?". His independent variable would be the age of the egg (fresh vs. aged), his dependent would be the amount of food coloring inside the shell (which would determine how much oxygen could really pass through the pores), and his controls would include the amount of food coloring used, its color, the amount of water used to soak the eggs etc.

If your son needs help with variables, this link is especially helpful!
https://www.sciencebuddies.org/science- ... bles.shtml

The independent variable is the variable that you are changing, the dependent is the variable that you want to observe (how does this thing change as a result of manipulating the independent variable), and the controls are factors in the experiment that you keep constant!

Hope this helped,

-JSK

Thank you so much JSK for your response. If he is not doing a variation, if all 3 eggs were from the same batch and socked in the same colored water, would there be an independent variable? He didn't change anything but treated all 3 eggs the same... If there is no independent variable, do you still note the dependent and controls? Sorry, this science project stuff is new for us!

angeliquekim wrote:Thank you so much JSK for your response. If he is not doing a variation, if all 3 eggs were from the same batch and socked in the same colored water, would there be an independent variable? He didn't change anything but treated all 3 eggs the same... If there is no independent variable, do you still note the dependent and controls? Sorry, this science project stuff is new for us!

Dear Ms. Kim,

If he isn't doing a variation, and all the eggs are exposed to the same conditions, then I'm afraid that there isn't an independent variable in that experiment (an independent variable is a variable that has to be manipulated to test whether that particular aspect of an experiment affects the results)! If there is no independent variable, then there is no dependent variable either (the dependent variable depends on the independent), and all aspects are treated as "controls". Your son will probably have to do a variation of the main experiment to get an independent and dependent variable!
Hope this helps!

-JSK