MYP Biology: Presenting Biological Data (Criterion C) Explained

Presenting biological data is assessed through Criterion C: Processing and evaluating, marked out of 8. Your teacher checks that you've processed raw data correctly, chosen an appropriate graph or table, interpreted trends accurately, and evaluated your hypothesis and method against the results you actually got.

Criterion C is one of four MYP Sciences criteria (A: Knowing and understanding, B: Inquiring and designing, C: Processing and evaluating, D: Reflecting on impacts). Marked out of 8, it focuses on what you do after collecting data — processing numbers, drawing graphs, spotting trends, and judging whether your results actually support your hypothesis.

Criterion C tasks use command terms like 'process', 'interpret', 'describe' and 'evaluate'. 'Process' means carry out a calculation (mean, percentage change); 'interpret' means explain what a pattern means biologically; 'evaluate' means weigh up strengths and weaknesses of your hypothesis or method using evidence from your own data.

Use a line graph for continuous data across a range (e.g. enzyme activity vs temperature), a bar chart for discrete or categorical data (e.g. mean leaf count per species), and a scatter graph when testing correlation between two continuous variables, like light intensity against photosynthesis rate.

A correctly presented graph has a title stating the relationship shown, labelled axes with units, an appropriate scale, clearly marked points, and a line of best fit rather than dot-to-dot joining where a trend is expected. Missing units or an unlabelled axis is the single most common mark loss I see marking these.

A strong conclusion states whether your hypothesis was supported, quotes actual data as evidence rather than saying 'the graph shows an increase', and explains the trend with biological reasoning. Vague, unsupported claims lose marks fast — examiners want your numbers linked to a mechanism.

Criterion B: Inquiring and designing covers planning — writing a testable hypothesis, identifying variables, designing a fair-test method. Criterion C: Processing and evaluating covers what happens after data collection — processing it, presenting it clearly, and evaluating your hypothesis and method against the results you actually obtained.

The three mistakes I mark down most often: bar charts used for continuous data, conclusions that restate the graph instead of explaining it biologically, and evaluations that list generic errors like 'human error' instead of specific, measurable sources of uncertainty tied to the actual method used.

Criterion C is marked out of 8, using four achievement-level bands (1-2, 3-4, 5-6, 7-8) described in the IB's MYP: Sciences guide. It's one of four equally weighted criteria — A, B, C and D — giving a maximum total of 32 marks for a unit or investigation task.

Yes. The IB's MYP: From Principles into Practice guide requires all four MYP Sciences criteria — A, B, C and D — to be assessed at least twice across each school year in Years 4 and 5. Schools build this into unit plans, so Criterion C usually appears in most data-based investigations.

Criterion C contributes a quarter of the total MYP Sciences score — 8 out of 32 marks — so consistently weak data presentation can pull down an otherwise strong grade even when your child understands the biology well. It's often the fastest criterion to improve with focused, targeted practice.

The quickest gains come from practising graph construction and conclusion-writing on past lab data, not re-reading theory. Ask your child to redo one graph from a recent assessment with correct axes, units and a trend line, then explain the trend aloud in one sentence using the actual numbers.