MYP Physics Criterion B: Inquiring & Designing — FAQ

You score well by nailing all three strands: a testable research question with a scientifically justified hypothesis, a variables table that actually explains why each control matters, and a method detailed enough that a classmate could repeat your experiment and get the same data. Vague reasoning is the biggest mark-loser.

Criterion B is planning — your hypothesis, variables and method, written before you touch any equipment. Criterion C is processing and evaluating — what you actually did with the data you collected, your graphs, calculations, and how reliable your results turned out to be. They're graded separately, even from the same investigation.

A good hypothesis states the predicted relationship between your independent and dependent variables, then justifies it with physics you've actually studied — not a guess. For example: 'As pendulum length increases, period increases, because period is proportional to the square root of length according to $T=2\pi \sqrt{L/g}$.'

A working experiment doesn't guarantee marks — Criterion B rewards the planning on paper, not the outcome. If your method is missing quantities (how many trials, what intervals, what equipment precision), or your variables table doesn't explain why you're controlling each factor, you'll sit at level 5-6 even with flawless data.

Detailed enough that another student in your class could follow it step-by-step and collect the same type of data without asking you a single question. That means exact quantities, equipment with its precision (e.g. 'metre ruler, ±1 mm'), number of trials, and safety considerations where relevant.

Listing variables without explaining why each control matters. Examiners want reasoning: 'room temperature is controlled because resistance in the wire changes with temperature, which would affect current independent of length' — not just 'temperature: controlled.'

Usually not on that specific task, since MYP criteria are typically assessed once per task and recorded as a best-fit level across the year. But you get multiple opportunities across the year to demonstrate Criterion B at a higher level — each new investigation is a fresh chance.

Criterion B is marked out of 8, split into four level bands: 0 (not achieved), 1-2, 3-4, 5-6, and 7-8. Like all four MYP Sciences criteria (A, B, C, D), each is worth 8 marks, giving a total of 32 raw marks that get converted into the final 1-7 MYP grade.

Yes — the strand descriptors for Criterion B don't change between MYP 4 and MYP 5; what shifts is the complexity of the physics you're expected to apply and the sophistication of your reasoning. A year 5 hypothesis is expected to draw on more advanced content, like circular motion or wave interference, than a year 4 one.

Yes — Criterion B counts equally alongside Criteria A, C and D. Each is worth 8 raw marks, and all four are added together (out of 32) before being converted to the final 1-7 grade using grade boundaries set by your school, following the IB's published MYP grade descriptors.

Ask your child to explain their hypothesis out loud before they write it — if they can't say why they expect a result, in physics terms, it's not ready yet. Reviewing past feedback for specific strand comments (i, ii or iii) is far more useful than general 'try harder' encouragement.

No — MYP is criterion-referenced, but individual schools set their own grade boundary conversions from the raw criteria totals (out of 32) to the final 1-7 grade, within guidance the IB provides. This means the same piece of work could convert slightly differently between two IB World Schools.