In science, a variable is something that can be changed, measured or controlled in an experiment. Scientists look at variables to understand how they affect things. A variable is any one of the things ...

A control variable (or scientific constant) in scientific experimentation is an experimental element which is constant and unchanged throughout the course of the investigation. Control variables could ...

Overview: Using segments from the PBS program: The Human Spark, students learn how to design and critique experiments with living subjects. In the Introductory Activity, students explore the steps ...