Science Buddies: "Ask an Expert"

I have to do an experimental design project, and I can't think of anything for the procedure, and the control variable. My topic question is: Does Vaccum Sealing Bag preserve foods longer then regular food storage bags. I know it sounds like a 4 year old can do it, But it has to sound like it was performed by an adult. So far this is what i put for my procedure

Procedure:
1. Get the vacuum sealing gallon bag and open it
2. Place 1 kilogram of strawberries into the bag
3. Get a Ziploc Gallon Bag and open it
4. Repeat step 2
5. Place both bags in the freezer

Questions I have:
I don't know how to explain this with more vocabulary in it.
What is the control variable?
What is the Independent and Dependent Variable?
What do I use to measure the data?
What is an annotated bibliography?

Hi! Check out this page https://www.sciencebuddies.org/science- ... thod.shtml. It discusses the scientific method. If you scroll down you can click on a variety of links (one of which is "variables"-which will talk about the independent/dependent variables).

As for measuring your data, you need to come up with a way of scoring the "freshness" of the strawberrys. You could look at the color, texture.....(for example). I would suggest doing a google search to identify a few things to measure.

Here is a link to writing a biography: https://www.sciencebuddies.org/science- ... aphy.shtml. Purdue OWL also has a good page discussing annotated biographies http://owl.english.purdue.edu/owl/resource/614/01/.

Good Luck!

Hi dgirl97,

A control variable is a part of the experiment that you do not change from condition to condition. For instance, making sure the sealed and unsealed food is kept at the same temperature. Or sealing the food in the same type of plastic. Or using the same piece of food (cut into pieces) in sealed and unsealed conditions. When you design an experiment to test two different conditions, you want to keep as many variables constant between those two conditions. For example, if you take some strawberries and you keep one sealed at room temperature and the other unsealed in the refrigerator, and you observe that the sealed strawberry goes bad before the unsealed strawberry, you won't know if it was due to the fact that it was sealed or the fact that it was kept at room temperature. Does that make sense?

And here's an excellent link that explains the Independent and Dependent Variable: http://nces.ed.gov/nceskids/help/user_g ... iables.asp.

I hope this helps!

-Dave