9.4 Evaluating a source
9.4.2 Coverage and selection
Determine who or what is included and excluded. A survey of current members cannot represent former members who left before the survey. Online reviews cannot be treated as a random sample of all users.
9.4.3 Definition and method
Two sources can use the same label while measuring different concepts. “Participation” could mean at least one activity per year, a registered program, a facility visit, or weekly exercise. Read the definition, questionnaire, calculation rule, and unit.
9.4.4 Timeliness and revision
Check whether the period aligns with the project and whether values are preliminary, revised, or final. A recent publication may still contain older reference-period data.