Monday, December 12, 2011

What does the variable and control in a science project mean?

Help! im doin a science project over Christmas break and i dont know what the variable means in a project! And i dont know what a control means!!!|||A quick example: to perform an experiment, you take two potatos.





One is placed in a cup with some water. (Variable or experimental)





One is placed in a cup with no water. (Control)





The one in the cup with water will show some differences, it will sprout and begin to grow roots.





The one without water will simply shrivel and decay, with only small eyes growing but not roots.





The variable subject showed the results of the experiment. The control subject showed what would normally happen if the experiment was not carried out. Thus the results of the experiment is the DIFFERENCE between the two subjects.|||In many experiments, you change something to see the results. The thing you change is the variable. For example, you could change the amount of sunlight a plant gets to see how it affects growth.


The control is an identical item which is not changed, for comparison. In the plant example, you would have an identical control plant which gets the same amount of sunlight every day. Then you would compare the two plants.|||The control is the part of the experiment that stays the same. The variable is the part you change to see if there is any effect from the things changed in the experiment.





For example: Doctors are testing a new drug. Half the people are given a dose of the drug (variable ) and the other half are given a sugar pill (control).





The control is what you compare the variable to to see how much of an effect it has.





What's you project idea?

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