Final participation, exclusion, and accommodation rates were presented in quality control tables for each grade and subject by geographic domains and school type. 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 (4, 8, and 12). Student-level participation rates were also below 85 percent for students in grade 12 public schools. As required by NCES standards, nonresponse bias analyses were conducted on each reporting group falling below the 85 percent participation threshold.