Assess students' ability to design a controlled investigation to test how varying light intensity affects plant growth: formulate a clear hypothesis, identify independent, dependent and controlled variables, choose appropriate controls and replication, specify materials and step-by-step procedures (including how to vary and measure light intensity and growth metrics such as height, leaf count or biomass), outline data-collection and analysis methods (averages, graphing, drawing conclusions), and discuss potential sources of error and safety considerations.