SLA Topics SLA Bibliography Vivian Cook
MLU (Mean Length of Utterance) in Morphemes
Record enough natural speech to yield at least one hundred consecutive utterances after stages 2 to 3
Transcribe the speech.
all utterances where it is unclear what the child said.
exclamations, mm, oh, etc, except when they form the entire utterance
false starts, want - want drink
Count the number of morphemes, both content and grammatical, counting as a
compound words, choo-choo, birthday etc
words with ie/y, mummy, doggie
irregular past tense, went
but including as separate morphemes:
· auxiliaries; will, , is, s, have, ve, etc
· all inflected endings -s, -ed, etc
Divide the total by the number of utterance to get the MLU in morphemes
L1 sources: Roger Brown, Paul Fletcher