The National Center for Education Statistics (NCES) and the National Assessment Governing Board have established participation rate standards that states and jurisdictions are required to meet in order to have their results published.
An additional standard has also been established that requires annotation of published results for states and jurisdictions whose sample participation rates, among one or more particular kinds of schools, are low enough to raise concerns about their representativeness.
This standard requires that a state or jurisdiction with otherwise adequately weighted school participation will receive a notation if the nonparticipating schools include a class of schools with similar characteristics, which together account for more than 5% of the state or jurisdiction's total weighted sample of schools. The classes of schools from which a state or jurisdiction need minimum school participation levels are as follows:
For more technical information on participation rate standards, see these sources: