Final participation, exclusion, and accommodation rates were presented in quality control tables for each grade and subject by reporting group. School-level participation rates were calculated as they had been calculated for previous assessments and according to National Center for Education Statistics (NCES) standards.
School-level participation rates were below 85 percent for private schools at all three grades and for public schools at grade 12 in all assessment subjects. Student-level participation rates were below 85 percent for students in public schools at grade 12 in all assessment subjects. As required by NCES standards, nonresponse bias analyses were conducted on each reporting group falling below the 85 percent participation threshold.