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)

Introduction

—coming soon—

Practice and continue

Practice

Primary and secondary data

Data collected yourself against someone else's records, and what each costs.

Next lesson

Data collection sheets

Designing collection sheets whose classes cover every value without overlapping.