Faculty of Arts, Charles University, Prague, Czech Republic.
Institute of Psychology, Czech Academy of Sciences, Prague, Czech Republic.
J Speech Lang Hear Res. 2024 Mar 11;67(3):837-852. doi: 10.1044/2023_JSLHR-23-00251. Epub 2024 Feb 28.
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.
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 (MLU) 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.
The different MLU measures based on different sample lengths correlated closely with MLU in transcripts of all utterances (all s > .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 MLU at 2;6 for MLU (β = .29) and grammar (β = .33) at 3;11 and vocabulary (β = .27) at 3;7.
MLU 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.
我们研究了平均话语长度（MLU）在捷克语中的性质，捷克语是一种形态复杂的斯拉夫语言。我们比较了基于不同单位和不同样本长度计算的 MLU 得分，并评估了其与另一种转录本和基于测试的测量方法的有效性。
109 名儿童在 2 岁 6 个月和 3 岁 11 个月时进行了自由游戏录制。我们比较了不同长度的转录本中的音节 MLU、词素 MLU 和单词 MLU（50、75、100 和所有可用的话语）。为了评估 MLU 的有效性，我们还计算了生产性语法指数（IPSyn）和不同单词数（NDW），并使用了接受性词汇和语法理解测试的结果。
基于不同样本长度的不同 MLU 测量与所有话语转录本中的 MLU 密切相关（所有 s >.87）。我们发现，在两个时间点，MLU、IPSyn 和 NDW 之间大多存在较强的相关性，而 MLU 与语法和词汇之间的相关性较弱或中等。回归模型显示，2 岁 6 个月时的 MLU 对 3 岁 11 个月时的 MLU（β =.29）和语法（β =.33）以及 3 岁 7 个月时的词汇（β =.27）具有显著的独特影响。
基于所有话语的 MLU 被证实是捷克语早期语言技能的有效测量方法，因为它在时间上是稳定的，并与其他基于转录本和基于测试的测量方法具有同时性和预测性的关系。
