TABLE 1.
Characteristics of schools, classes, and children in each study condition.
| Characteristics |
Intervention group |
Control group |
| Mean (SD) | Mean (SD) | |
| School-level characteristics | ||
| Number of schools | 4 | 4 |
| Number of students | 22.25 (6.95) | 25.00 (10.42) |
| Socioeconomic status1 | 4 | 5 |
| Class-level characteristics (K2) | ||
| Number of students | 6.79 (0.98) | 7.57 (1.45) |
| Number of classes (and teachers) | 14 | 14 |
| Teachers, years of teaching | 18.54 (9.58) | 17.42 (13.85) |
| Teachers, gender (female, %) | 100% | 100% |
| Child-level characteristics, entire sample (N = 189) | ||
| Socioeconomic status (ISEI)2 | 53.44 (23.02) | 55.31 (21.91) |
| Gender (female, %) | 45% | 44% |
| Second language learners (%)3 | 46% | 38% |
| Child-level characteristics, subgroup low oral language (n = 63) | ||
| Socioeconomic status (ISEI)2 | 41.67 (21.09) | 42.90 (20.49) |
| Gender (female, %) | 54% | 44% |
| Second language learners (%)3 | 84% | 75% |
K2 = second year of kindergarten; 1average ISEI of municipality: 1 = 35 ≤ 40, 2 = 40 ≤ 45, 3 = 45 ≤ 50, 4 = 50 ≤ 55, 5 = 55 ≤ 60, 6 = 60 ≤ 65; 2ISEI, International Socio-Economic Index of occupational status; 3second language learners are defined here as children for whom Luxembourgish was not the dominant home language.