Shop Windows to the Universe

Become a nitrogen atom in the nitrogen cycle in our Traveling Nitrogen Classroom Activity Kit/Game. See all our games, activity kits and classroom activities.
A student studying for a test. As time studying for the test goes up, so should test score.
Click on image for full size
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 truckís sales are really high, itís probably not snowing.

Finally, some variables will have no clear relationship or correlation.

Last modified January 25, 2008 by Jennifer Bergman.

Shop Windows to the Universe Science Store!

Our online store includes fun classroom activities for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist are also full of classroom activities on different topics in Earth and space science!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Sun's Effect on Earth's Weather (Wind)

The Sun affects many things on Earth. One of the main things the Sun does is warm our planet, including the atmosphere. This energy drives much of Earth's weather. The solar cycle is the rise and fall...more

A Trip to the Observatory

Have you ever wondered what it would be like to take a trip to an observatory to use the telescope? In February 2006, astronomer Travis Metcalfe was granted 7 nights of observing time on one of the telescopes...more

A Trip to the Observatory - Transcript

I'm Travis Metcalfe, an astronomer at the National Center for Atmospheric Research in Boulder, Colorado. I made this short video for anyone who's ever wondered what it's like to take a trip to the observatory...more

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...more

Hipparchus

Hipparchus was a Greek astronomer who lived between 190-120 B.C. He is considered the father of trigonometry, a branch of mathematics which studies the angles of sides of triangles. Hipparchus also developed...more

James Adamson

James Adamson is an American astronaut who was born in New York in 1946. From 1965-1980, he served with the Army and the Navy. Adamson became an astronaut in 1984. He has flown on two space missions....more

Tom Akers

Tom Akers is an American astronaut who was born on May 20, 1951 in Missouri. Before he was an astronaut, Akers was a park ranger, teacher, and Air Force pilot. He has flown 25 different kinds of airplanes....more

Joseph Allen

Joseph Allen is an American astronaut who was born on June 27, 1937 in Indiana. Before he became an astronaut, Allen was a physicist who taught at the University of Washington. Allen became an astronaut...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF