*I'm tired. It's late. I've stared at the question for 3 hours and I don't even know what I'm doing anymore.*

1. a) A group of students plans to investigate which is better for the environment: glass bottles or

aluminum cans. They intend to use a formal method of investigation and make a list of pros and

cons for each type of container. They need to research the technology used and the post-consumer

fates of bottles and cans. The students will first find out how much energy is used to make each type

of container.

What scientific methods do the students need to use to get unbiased results in their comparative

investigation?