The student clearly stated the independent variable as the concentration of citric acid and the dependent variable as the antioxidative capacity of black tea in the research question. The methodology was thoroughly described, including the methods of analysis and the rationale behind the measurement techniques used. Additionally, the study effectively discussed controlled variables, safety, and environmental considerations, while also providing a detailed procedural outline that facilitated reproducibility. However, the student failed to address the ethical issues associated with the investigation, not explain their absence. Overall, the student demonstrated a comprehensive understanding of the investigation's requirements and methodology.
