Author note — to cover

Distinguish data collected yourself from data taken from existing sources, with one advantage and one drawback of each: control and relevance versus speed and cost. Definition and justification questions only. Not named in the 2013 DfE content, so keep it brief and low-stakes; it supports the sampling pages. Both tiers. (S1)

• Fluency — direct questions on primary and secondary data, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).