Two vocabulary measurements were used in the study: an Icelandic version of the Peabody Picture Vocabulary Test (PPVT-‐ 4) which has been translated and norm referenced for Icelandic children and a standardized Polish vocabulary test, Picture Vocabulary Test–Comprehension (OTSR).
Í rannsókninni voru notaðar tvær orðaforða mælingar: íslenskt orðaforðapróf PPTV-‐ 4 (e. Peabody Picture Vocabulary Test) og pólskt staðlað orðaforðapróf OTSR (e. Picture Vocabulary Test–Comprehension).