They have done the control in the skill building activity. Insist that each group do a different experiment, testing a different variable. To ensure inquiry, do not help them as they decide. Observations will need to be made for a period of time, probably a week or two. Experiment has a control, logical and clear procedures, data is recorded and thoroughly analyzed.
Graphs are present.
Conclusions thorough and thoughtful. 6 Competent Completes all steps. Experiment may lack control, procedures lack thoroughness. Data is recorded, analysis not complete. Conclusions too brief.