Assessment design

Every question measures something. The work is making sure it measures the thing you meant, because the alternatives — reading speed, familiarity with the format, willingness to guess — are always available and are usually easier for the student to use.

Name the inference before writing the item

An assessment is an argument: the student did this, therefore they can do that. The argument is where assessments fail, and it fails silently.

Write down the claim first — "can decompose a two-digit number into tens and ones" — then ask what performance would be evidence for it, and what performance would be evidence against. An item that a student who lacks the skill can still get right is not evidence. An item that a student who has the skill can still get wrong, for reasons unrelated to it, is worse: it produces a false negative that gets acted on.

The most common unrelated reason is reading. Any item whose stem is harder to read than the skill is to perform has quietly become a reading assessment.