This curriculum unit for middle school features two lessons in which students design experiments to test their own hypotheses. In the first lesson, students gather and record simple data about drops of different fluids -- but that is not the primary point of the activity. Instead, students must analyze their own findings and generate plausible explanations based upon the evidence.

In the second lesson, students develop testable hypotheses about the amount of mass lost in gum after chewing. They test both sugared and sugar-free gums.  Again, the main point is not data collection. This experiment promotes understanding of the importance of a control in a scientific experimentation.

Editor's Note: This curricular unit is offered in segments. The entire unit takes about two weeks, but may be parceled into smaller modules requiring 2-3 days for completion.