Sampling and participation

Define sample and participation denominators

A snapshot requires an explicit sampling frame and assessment window. Retain design information and separate unit nonresponse from item missingness. A convenience sample needs a defensible limit on population generalization.

Flow diagram

Steps

Define population and sampling frame

Specify the target population and assessment period.

Select the sample

Specify probability or nonprobability sampling and the sampling frame. Retain selection probabilities, strata and clusters where relevant; weighting alone cannot establish representativeness.

Approach selected participants

Track eligible invitations and contact attempts.

Record participation and nonresponse

Distinguish refusals, noncontacts and ineligibility.

Define analysis denominators

Retain strata, cluster and weight information and item-specific denominators.