Language assessment of Swedish 3-year-olds using a protocol of natural speech: PLUS-3--productive language USe at 3

PLUS-3 is a new Swedish protocol of natural speech in 3-year-old children. Two studies are reported with 27 (11 girls and 16 boys) and 12 children (4 girls and 8 boys), respectively. The children were tape-recorded by their parents in dialogues based on picture books. The reliability of PLUS-3 was satisfactory (88%; inter-rater agreement), as was the concurrent validity measured by correlation with a grammar scale (rs = 0.53; p < 0.01). PLUS-3 correlated significantly with slightly modified mean length of utterance (MLU) measures (rs = 0.80; p < 0.01) and with lexical diversity (rs = 0.68; p < 0.02). In total, 30 two-morpheme utterances were sufficient to capture the language level of a child. PLUS-3 was significantly associated with communicative measures collected 14 months earlier (5 out of 8 measures, p < 0.05).