IB Biology HL Internal Assessment Example

The student framed a focused, measurable research question with a clear independent variable, dependent measure, and biological system.

The student gave a relevant biochemical rationale for why green tea might affect lipase activity and why the chosen endpoint could change.

The student included several sound design features such as a control, repeated trials, and controlled volumes and concentrations.

The reaction temperature is inconsistent across the description, which weakens clarity and validity.

The green-tea treatment is not fully operationally defined as a verified concentration of extract or catechins.

Some procedural details are incomplete, so another reader could not reproduce every step without uncertainty.

The student's raw data are organized clearly and consistently across five repeats for each concentration.

The student processed the results appropriately by calculating means, standard deviations, and a graph with error bars.

The student used quantitative analysis to show a strong overall trend rather than relying only on description.

The precision of the recorded raw timings does not fully match the stated measurement uncertainty.

The student's uncertainty treatment does not adequately account for the much larger uncertainty in judging the visual endpoint.

The analysis would be stronger if the student converted time into a rate measure and treated the correlation evidence more cautiously.