How to Design a Fair Marking Scheme for a CBC Structured Question

A structured question is only as fair as the marking scheme behind it. Two teachers can write the exact same question and produce very different marking experiences — one where every learner and every marker knows exactly what earns a mark, and one where marks get awarded inconsistently depending on who's grading that day. The difference almost always comes down to how carefully the marks were planned before the exam was ever printed.

Nest Your Sub-Parts, and Mean It

CBC structured questions are built to nest: a main question (a), broken into (i) and (ii), sometimes followed by (b) and (c). This isn't just formatting — each sub-part should test one discrete thing. If (a)(i) and (a)(ii) are really asking the same thing in two different sentences, you haven't created two marking opportunities, you've created one question with padding.

A good nested structure typically looks like: smaller, atomic sub-parts worth 1-2 marks each for single facts or single steps, and occasionally a larger sub-part worth 5-6 marks where the learner has to combine several ideas or show an extended process (an explanation, a calculation with several steps, a short paragraph). The size of the mark allocation should match the size of the cognitive task — don't give 1 mark for something that genuinely requires three correct steps to get right.

Make the Marks Add Up — Literally

Every section of a paper has a stated total, and every question's marks should sum to it exactly. This sounds obvious, but it's one of the most common technical errors in hand-built marking schemes: a section stated as "10 marks" that actually totals 11 or 9 once you add up every sub-part. Before you finalise a paper, physically add up the marks in every question and check the sum against the section header. It takes two minutes and it's the difference between a paper that behaves the way it claims to and one that quietly under- or over-allocates marks to a section.

This also matters for weighting: if Section B is meant to carry 30% of the paper's total, the marks inside Section B need to genuinely add up to that proportion — not close to it.

Reward the Method, Not Just the Final Number

This is especially important in Mathematics and the sciences. A marking scheme that only awards marks for the final correct answer punishes a learner who understood the concept and used the right method but made a small arithmetic slip along the way — while rewarding a learner who copied a correct final answer without understanding how to get there. Neither outcome reflects what you actually want to measure.

The fix is to build your marking scheme around the steps, not just the destination:

• Award a mark for identifying the correct method or formula, even if the final computation is wrong.
• Award a mark for correct working at each intermediate step.
• Reserve the final mark specifically for the correct final answer, arrived at through the shown working.

For example, a 3-mark calculation question might allocate 1 mark for setting up the correct equation, 1 mark for correct substitution, and 1 mark for the correct final answer — rather than all 3 marks resting on getting the final number exactly right.

Write the Marking Scheme Alongside the Question, Not After

The most reliable way to end up with a fair, clean marking scheme is to write it at the same time as the question — not as an afterthought once the paper is finished. When you draft a structured question, immediately draft what a full-mark answer looks like, sub-part by sub-part. If you struggle to say precisely what earns each mark, that's usually a sign the question itself needs tightening, not just the scheme.

A Quick Checklist Before You Finalise a Paper

• Does each sub-part test one discrete idea, not a repeat of the previous one?
• Do the marks for each question sum to the section total, and does the section total sum to the paper total?
• For calculation or process-based questions, does the scheme award marks for correct method and working, not only the final answer?
• Could two different markers, using this scheme, arrive at the same mark for the same answer script?

That last question is really the test of the whole exercise. A marking scheme isn't just a record of what you meant when you wrote the question — it's the instrument that makes your grading consistent, defensible, and fair to every learner who sits the paper.