Mean length of utterance
Encyclopedia
Mean Length of Utterance (or MLU) is a measure of linguistic productivity in children. It is traditionally calculated by collecting 100 utterance
s spoken by a child and dividing the number of morpheme
s by the number of utterances. A higher MLU is taken to indicate a higher level of language proficiency.
A study by Bishop and Adams (1990) suggests that MLU at 4.5 is a good predictor of reading ability at age 8. Nonetheless MLU is considered controversial, and should not be used as the only diagnostic measure of language proficiency in children.
Utterance
In spoken language analysis an utterance is a complete unit of speech. It is generally but not always bounded by silence.It can be represented and delineated in written language in many ways. Note that in such areas of research utterances do not exist in written language, only their representations...
s spoken by a child and dividing the number of morpheme
Morpheme
In linguistics, a morpheme is the smallest semantically meaningful unit in a language. The field of study dedicated to morphemes is called morphology. A morpheme is not identical to a word, and the principal difference between the two is that a morpheme may or may not stand alone, whereas a word,...
s by the number of utterances. A higher MLU is taken to indicate a higher level of language proficiency.
A study by Bishop and Adams (1990) suggests that MLU at 4.5 is a good predictor of reading ability at age 8. Nonetheless MLU is considered controversial, and should not be used as the only diagnostic measure of language proficiency in children.
External links
- The Effect of Coffee Consumption on Adults’ Average MLU at the Breakfast Table: A humorous article demonstrating some of the criticisms of MLU—namely that extra-linguistic factors can greatly affect MLU.