Mean Length of Utterance in Czech Toddlers: Validity Estimates and Comparison of Words, Morphemes, and Syllables

0584693 - PSÚ 2025 US eng J - Journal Article
Matiasovitsová, K. - Čechová, P. - Sláma, J. - Homolková, K. - Smolík, Filip
Mean Length of Utterance in Czech Toddlers: Validity Estimates and Comparison of Words, Morphemes, and Syllables.
Journal of Speech Language and Hearing Research. Roč. 67, č. 3 (2024), s. 837-852. ISSN 1092-4388. E-ISSN 1558-9102
Institutional support: RVO:68081740
Keywords : child * child language * child preschool * Czech Republic * humans * language * language tests * linguistics * vocabulary
OECD category: Psychology (including human - machine relations)
Impact factor: 2.6, year: 2022
Method of publishing: Limited access

PURPOSE: We examined the properties of mean length of utterance (MLU) in Czech, a morphologically complex Slavic language. We compared the scores of MLU calculated in different units and based on different sample lengths and assessed its validity against another transcript and test-based measures. METHOD: One hundred nine children were recorded during free-play at 2,6 and 3,11 (years,months). We compared MLU in syllables, morphemes, and words (MLUw) in transcripts of different lengths (50, 75, 100, and all available utterances). For evaluating the validity of MLU, we also calculated Index of Productive Syntax (IPSyn) and number of different words (NDW) and used results of receptive vocabulary and grammar comprehension tests. RESULTS: The different MLU measures based on different sample lengths correlated closely with MLU in transcripts of all utterances (all rs > .87). We found mostly strong correlations between MLU, IPSyn, and NDW at both time points and weak or moderate correlations between MLU and grammar and vocabulary. Regression models showed the significant unique effect of MLUw at 2,6 for MLUw (β = .29) and grammar (β = .33) at 3,11 and vocabulary (β = .27) at 3,7. CONCLUSION: MLUw based on all utterances was confirmed as a valid measure of early language skills in Czech, as it is stable in time and shows concurrent and predictive relations with other transcript-based and test-based measures.
Permanent Link: https://hdl.handle.net/11104/0352538