MLU
Pronunciation: /ɛm ɛl juː/
Also written as: MLU — Mean Length of Utterance
Mean Length of Utterance, a measure of grammatical development calculated by dividing total morphemes by number of utterances.
Full Definition
Mean Length of Utterance (MLU) is a quantitative measure used to assess grammatical and syntactic development in children's language. Calculated by dividing the total number of morphemes in a language sample by the total number of utterances, MLU provides insight into sentence complexity and grammatical maturity. Speech-language pathologists use MLU as part of comprehensive language assessment, particularly for children ages 2-5 years. While useful for tracking language development, MLU should be interpreted alongside other measures as it may not capture all aspects of linguistic competence, and cultural and dialectal variations can affect results.
Usage
Usage note: Specify whether calculated in morphemes or words (MLU-m vs MLU-w). Standard calculation uses morphemes.
In Context
- "The language sample analysis revealed an MLU of 3.2 morphemes, indicating age-appropriate grammatical development." — Assessment report
- "MLU calculations excluded immediate imitations and unintelligible utterances per standard protocol." — Clinical methodology note