IB Biology SL Internal Assessment Example

The student sets up a focused, testable investigation with a clear biological context and a well-defined independent and dependent variable.

The student explains the scientific rationale for using beetroot tissue and colorimetry in a way that shows understanding rather than simple description.

The student includes relevant controls and repetition that support a fair comparison across pH treatments.

Some procedural details are still missing, especially around solution preparation, sample dimensions, and how consistency was maintained across trials.

A few methodological choices are described too generally to allow complete replication, such as rinsing, temperature control, and blanking/calibration steps.

The rationale for some design choices could be made even sharper by linking them more explicitly to the hypothesis and prior research.

The student's raw data are clearly organized and the processing from repeats to means and standard deviations is appropriate.

The student communicates the main numerical results well through tables and a graph that are directly relevant to the question.

The student makes a genuine attempt to consider uncertainty rather than relying only on averages.

Some parts of the presentation could be clearer, especially the notation and the explanation of the error bars.

The uncertainty treatment is incomplete because not all important sources of measurement uncertainty are addressed.

The interpretation of the processed data is not always cautious enough when the spread in the results is large.