MYP Chemistry: Writing a Strong Chemistry Lab Report

A strong MYP Chemistry lab report explains why you did an experiment, how you controlled variables, what your data shows, and how reliable it actually is. It's assessed against MYP Sciences Criterion B (design) and Criterion C (processing/evaluating) — not just neat handwriting or a completed method.

A typical MYP lab report has: Research Question, Hypothesis, Variables (independent/dependent/controlled), Materials, Method, Results (data table + graph), Processing (calculations), Conclusion, and Evaluation. Not every criterion strand needs every section — check which command terms your teacher's task sheet actually assesses.

A good hypothesis states the predicted relationship between your independent and dependent variables and gives a scientific reason. For example: 'As concentration of HCl increases, reaction rate with magnesium ribbon will increase, because higher concentration means more frequent particle collisions (collision theory).'

Criterion B, 'Inquiring and Designing', assesses your research question, hypothesis, and experimental design — including variables, controls, and safety/ethical considerations. It's marked out of 8 in MYP 4-5, with strands assessing whether your design would let someone else reliably repeat your experiment.

Criterion C, 'Processing and Evaluating', is marked out of 8 and assesses whether you can accurately process data, identify trends, and evaluate the validity of your method and conclusion. This is where most MYP 4-5 students lose marks — not on results, but on evaluation.

A strong evaluation compares your result to expected/theoretical values, calculates percentage error where relevant, names specific limitations in your method, and proposes realistic improvements — not just 'repeat the experiment more times.'

Percentage error compares your result to an accepted value: % error = |experimental − accepted| / accepted × 100. Percentage uncertainty reflects your equipment's precision: % uncertainty = (uncertainty of instrument / measured value) × 100. Both should appear in Criterion C processing.

The three I see most often in MYP 4-5: vague hypotheses with no scientific reasoning, data tables with no units or uncertainties, and evaluations that blame 'human error' instead of naming a specific, fixable limitation in the method or equipment.

There's no official MYP page-count rule — length depends entirely on the task's complexity and which criteria strands are assessed. A report is the right length when every section fully addresses its command terms; padding with unnecessary background research won't raise your grade.

Yes, if your data has a trend worth showing — most quantitative investigations need at least one graph with labelled axes, units, a suitable scale, and (where appropriate) a line of best fit. Criterion C explicitly assesses your ability to process data visually as well as numerically.

Lab reports are graded against the same four MYP Sciences criteria (A: Knowing and Understanding, B: Inquiring and Designing, C: Processing and Evaluating, D: Reflecting on Impacts) used across all science tasks — but a lab report specifically targets Criteria B and C, while a research project might target A and D instead.

The single most useful thing you can do is ask your child to explain their conclusion out loud before they submit it — if they can't say why the result happened chemically, the written evaluation usually won't score well either. Reviewing the task sheet's assessed criteria together also helps them target the right sections.

Yes — MYP lab report skills (hypothesis writing, variable control, error evaluation) map directly onto DP Chemistry's internal assessment and general lab work. Students who master Criterion C evaluation in MYP 4-5 typically write far stronger DP scientific investigation reports two years later.