A student studying for a test. As time studying for the test goes up, so should test score.
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Courtesy of Freeze Clip Art
Correlations in Science
When scientists do an experiment, they looking to see if two variables are related. A variable is something that changes.
Sometimes variables are related (or correlated) in a positive way. That is, as one variable goes up, the other one goes up too. In an experiment to see if amount of time studying for a test affects student test score, the two variables are probably positively related. As time studying for a test goes up, test score probably goes up too.
Sometimes two variables can have a negative correlation. As one variable goes up the other always goes down. For example, the total sales in a day for an ice cream truck and the total snowfall for that same day might have negative correlation. On days with lots of snow, not many people are buying ice cream from the truck. On days where the ice cream truck’s sales are really high, it’s probably not snowing.
Finally, some variables will have no clear relationship or correlation.
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