Assess students' ability to design a fair experiment to test how different amounts of sunlight affect plant growth by having them: state a testable hypothesis; identify independent, dependent, and controlled variables; choose suitable plant species, sample size, and materials; outline a step-by-step procedure with replication; select measurement methods (e.g., height, leaf count) and observation schedule; describe how to record and graph data; and explain how to draw evidence-based conclusions and address possible sources of error and improvements.