The student clearly states the independent variable as the percentage concentration of sugar in the solution and the dependent variable as the refractive index, demonstrating a solid understanding of their relationship. However, the research question lacks a specification of the method of analysis for the refractive index, which could enhance clarity. The student provides a comprehensive background theory relevant to the research question and clearly explains the techniques used for measuring the variables. While the methodology is well-structured and allows for reproducibility, the student does not adequately discuss the number of trials, controlled variables, or safety issues associated with the investigation. Nonetheless, ethical and environmental considerations are appropriately addressed, reflecting an awareness of these aspects in the research.
