Development of an intelligence test for children aged from four to eleven. Construction and validation of RAKIT ( gereviseerde Amsterdamse Kinder Intelligentie Test ), an intelligence test for children aged 4-11. Three sub-populations were tested: normal primary education, special primary education and ethnic minorities ( immigrant children ). Comparisons were made with WISC-R and CITO test data on school achievements. Background variables: basic characteristics / place of birth / residence / characteristics of parental family / household / occupation / employment / education / social class