ICCS 2009 Technical Report - IEA

B.2. Belgium (Flemish)• School-level exclusions consisted of schools in the system of education for children withspecial needs.• Explicit stratification was performed by school size (large, medium/small), resulting in twoexplicit strata.• Implicit stratification was applied by province (five levels), educational network (twolevels), and educational stream (two levels), giving a total of 32 implicit strata.• Two classrooms were sampled in the 10 largest schools (MOS ≥275).• Schools in the “large” stratum were sampled with equal probabilities.Table B.2.1: Allocation of student sample in Belgium (Flemish)School Participation Status— Student SurveyParticipating SchoolsExplicit Strata Total IneligibleNon-ParticipatingSampled Schools Schools Sampled First Second Schoolsreplacement replacementLarge 40 0 30 7 0 3Medium/small 120 1 86 21 7 5Total 160 1 116 28 7 8Table B.2.2: Allocation of teacher sample in Belgium (Flemish)School Participation Status—Teacher SurveyParticipating SchoolsExplicit Strata Total IneligibleNon-ParticipatingSampled Schools Schools Sampled First Second Schoolsreplacement replacementLarge 40 0 27 7 0 6Medium/small 120 1 76 19 6 18Total 160 1 103 26 6 24Note: 15 schools were regarded as non-participating because the within-school participation rate was below 50%.B.3. Bulgaria• Schools for children with special education needs and schools with fewer than fivestudents in the target grade were excluded at the school level.• Explicit stratification was performed by region, resulting in 11 explicit strata.• Implicit stratification was applied by school type (general, profiled, vocational) and size ofsettlement for school type “general” (small town, medium-size town, large town), giving atotal of 54 implicit strata.Appendices287