Klee T, Schaffer M, May S, Membrino I, Mougey K
Vanderbilt University School of Medicine, Nashville, TN.
J Speech Hear Disord. 1989 May;54(2):226-33. doi: 10.1044/jshd.5402.226.
The relation between age and mean length of utterance in morphemes (MLU) was evaluated in a sample of 48 preschool children between 24 and 50 months of age. Twenty-four of these children were diagnosed as having a specific language impairment, and 24 were considered language normal. The groups were matched on age, race, sex, and parental education level. A majority of the children in each group were from lower-middle-class backgrounds. MLU was derived from 20-min mother-child conversations as the dyad engaged in free play. The results showed that (a) age and MLU were significantly correlated in the normal group (r = .75) and in the group of specifically language-impaired children (r = .77), (b) the predicted MLU of the language-impaired group was lower than that of the normal group across the age range, and (c) the rate of MLU change in each group was similar. The age-MLU relation observed in the lower-middle-class normal children compared favorably to that reported previously for middle- to upper-middle-class children (Miller & Chapman, 1981). The finding that MLU changed at a similar rate in the normal and language-impaired groups is evaluated in light of the observation that childhood language disability is usually associated with slower rates of language development.
在一个由48名年龄在24至50个月的学龄前儿童组成的样本中，评估了年龄与语素平均语句长度（MLU）之间的关系。其中24名儿童被诊断为患有特定语言障碍，另外24名被认为语言正常。两组在年龄、种族、性别和父母教育水平方面进行了匹配。每组中的大多数儿童来自中下层阶级背景。MLU来自于母婴在自由玩耍时进行的20分钟对话。结果表明：（a）在正常组（r = 0.75）和特定语言障碍儿童组（r = 0.77）中，年龄与MLU显著相关；（b）在整个年龄范围内，语言障碍组的预测MLU低于正常组；（c）每组中MLU的变化率相似。在中下层阶级正常儿童中观察到的年龄-MLU关系与之前针对中上层阶级儿童报道的情况（Miller & Chapman，1981）相比更有利。鉴于儿童语言障碍通常与较慢的语言发展速度相关这一观察结果，对正常组和语言障碍组中MLU以相似速率变化这一发现进行了评估。
