ICCS 2009 Technical Report - IEA

B.23. Lithuania• Special needs schools, very small schools (fewer than five students in the target grade),hospital schools, and students taught in Belarusian were excluded at the school level.• Explicit stratification was performed by language of instruction (Lithuanian, Polish,Russian) and community size (Vilnius (capital), other major cities, medium-size cities, smallcities, other), resulting in seven explicit strata.• Implicit stratification was applied by school type (gymnasium, secondary, basic, otherschool type), giving a total of 25 implicit strata.• Over-sampling of Russian and Polish language schools. The disproportional allocation wastaken into account when sampling weights were computed.Table B.23: Allocation of student sample and teacher sample in LithuaniaSchool Participation Status—Student Survey and Teacher SurveyParticipating SchoolsExplicit Strata Total IneligibleNon-ParticipatingSampled Schools Schools Sampled First Second Schoolsreplacement replacementRussian 37 0 37 0 0 0Polish 30 0 29 0 0 1Lithuanian— 15 0 15 0 0 0Vilnius (capital)Lithuanian—other 30 0 30 0 0 0major citiesLithuanian— 14 0 14 0 0 0medium-size citiesLithuanian—small 29 0 29 0 0 0citiesLithuanian—other 45 0 44 1 0 0Total 200 0 198 1 0 1B.24. Luxembourg• All schools were sampled.• Special needs schools were excluded at the school level.• All enseignement secondaire and enseignement secondaire technique classes were selected in eachschool. In addition, one modulaire class was randomly sampled per school whenever theschool had these classes.• No explicit stratification was performed.• No implicit stratification was applied.Table B.24.1: Allocation of student sample in LuxembourgSchool Participation Status—Student SurveyParticipating SchoolsExplicit Strata Total IneligibleNon-ParticipatingSampled Schools Schools Sampled First Second Schoolsreplacement replacementNone 31 0 31 0 0 0Total 31 0 31 0 0 0302 ICCS 2009 technical report