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). All Theses and Dissertations. 3274.
child language, MLU, MLU2