Mean length of utterance (MLU) is widely used in child language sample analysis as a way to quantify language development. The current study examines the split-half reliability of MLU and two alternative measures: MLU2 and median length of utterance (MdLU). The effects of utterance segmentation into phonological units (P-units) or communication units (C-units) on reliability were also studied. Sixty conversational child language samples were used which included ten children with language impairment. All measures were found to have high levels of split-half reliability, with MLU and MLU2 having higher levels of reliability than MdLU. There was no significant difference between MLU and MLU2. The differences in reliability when segmented into P-units or C-units were inconsistent. Overall, MLU and MLU2 are adequately reliable measures for clinical use.
College and Department
David O. McKay School of Education; Communication Disorders
BYU ScholarsArchive Citation
Bigelow, Katherine Marie, "Reliability of the Mean Length of Utterance Measure in Samples of Children's Language" (2012). Theses and Dissertations. 3274.
child language, MLU, MLU2