Science Buddies: "Ask an Expert"

My 3rd grade daughter has completed her science fair project already but needs to submit to a second fair in our area. She did a survey of 600 kids, all in the same age group,to answer these three questions. What is the most common cause of broken bones in kids? What is the most commonly broken bone by kids? and Who breaks more bones, boys or girls? The judge at the first fair said she needed to list her independent and dependent variables but we are having a hard time determining those since this was not an experiment, rather an observation.

Would the independent variables be, activities that cause broken bones, gender, and different types of bones? And would the dependent variable be broken bones?

Any help on this matter would be greatly appreciated.

Thanks!

Hello,

Welcome to Science Buddies! Your daughter has a very interesting project, and you are exactly right regarding the variables.

Note that the dependent variable is the one that you measure, so you are correct that the (number of) broken bones would be your dependent variable. The independent variable is the one that causes the dependent variable to change, so your independent variables are the causes of broken bones, the type of bone, and gender.

To help your daughter with the idea, here is the Science Buddies information about variables: https://www.sciencebuddies.org/science- ... bles.shtml

Please post again (in this same thread) if you have more questions.

Heather

Hello,

Thank you for responding.

The IV or independent variable is what you change a scientist. So the questions could be an IV...or the two groups: boys & girls
The DV or dependent variable is what changes from the IV. So the response or answers to the questions.

Hopefully this helps. Please feel free to ask any more questions.

Thanks