You can follow some links on the page you linked to and end up on one called "COVID-19 Infection Survey: methods and further information". This is a direct link

You can follow some links on the page you linked to and end up on one called "COVID-19 Infection Survey: methods and further information". This is a direct link to the section "Sampling" there: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/methodologies/covid19infectionsurveypilotmethodsandfurtherinformation#study-design-sampling https://www.ons.gov.uk/peoplepopulationandcommunity/healthan...