Ricardo came up with three different designs for paper airplanes. He would like to find out which design flies the farthest. Ricardo plans to fly each paper airplane five times. Wha step should Ricardo take after he flies each plane?

A scientist set up containers to collect water in three spots around town. He wanted to find out how much rain falls in each area. What should the scientist record when looking at each container?

The table below shows the vitamin C content in some common fruits and vegetables. Which conclusion is best supported by the data in the table?

Scientists want to determine whether watching television affects a child's ability to learn to read. The experimental group watches television for 2 hours a day. What should the control group do?

A team of students wants to find out what time of day squirrels in a forest are most active. They observe squirrels in a forest for five days. They record the period of time of any squirrel activity they see and describe the details of that activity. This investigation is not an experiment. Why?