Proctor-Williams Kerry, Fey Marc E
Department of Communicative Disorders, East Tennessee State University, 100 Central Receiving Drive, Johnson City, TN 37614, USA.
J Speech Lang Hear Res. 2007 Aug;50(4):1029-47. doi: 10.1044/1092-4388(2007/072).
Children with specific language impairment (SLI) lag behind children with typical language (TL) in their grammatical development, despite equivalent early exposure to recasts in conversation (M. E. Fey, T. E. Krulik, D. F. Loeb, & K. Proctor-Williams, 1999) and the ability to learn from recasts in intervention as quickly as do children with TL (K. E. Nelson, S. Camarata, J. Welsh, L. Butovsky, & M. Camarata, 1996). This experiment tested whether this apparent paradox could be attributed to variations in the density of recasts in conversation versus intervention.
Thirteen children (7-8 years of age) with SLI and 13 language-similar children (5-6 years of age) with TL were exposed to 3 recast densities of novel irregular past tense verbs (none, conversation-like, intervention-like) over 5 sessions. Outcomes were based on spontaneous conversational productions and a post-test probe.
As predicted, at conversation-like densities, children with TL more accurately produced the target verbs they heard in recasts than in nonrecast models (d = 0.58), children with SLI showed no differences, and children with TL produced the verbs more accurately than did children with SLI (d = 0.54). Contrary to expectations, at higher intervention-like recast densities, the SLI group did not improve their accuracy, and the TL group performances were significantly poorer (d = 0.47).
At conversational levels, recasts facilitated greater verb learning than models alone but only in the TL group. Increasing recast density to the modest levels in this brief intervention experiment did not benefit children with SLI and led to poorer learning for children with TL. To optimize learning, efficiency of recast distribution as well as rate must be considered.
尽管特定语言障碍（SLI）儿童与典型语言（TL）儿童在对话中接受复述的早期机会相当（M.E.费伊、T.E.克鲁利克、D.F.勒布和K.普罗克特 - 威廉姆斯，1999），并且在干预中从复述中学习的能力与TL儿童一样快（K.E.尼尔森、S.卡马拉塔、J.威尔士、L.布托夫斯基和M.卡马拉塔，1996），但SLI儿童在语法发展方面仍落后于TL儿童。本实验测试了这种明显的矛盾是否可归因于对话与干预中复述密度的差异。
13名7 - 8岁的SLI儿童和13名5 - 6岁语言能力相似的TL儿童在5个阶段中接触3种复述密度的新颖不规则过去时动词（无、类似对话、类似干预）。结果基于自发对话产出和后测探测。
正如预期的那样，在类似对话的密度下，TL儿童在复述中听到的目标动词产出比在非复述模型中更准确（d = 0.58），SLI儿童没有差异，并且TL儿童比SLI儿童更准确地产出动词（d = 0.54）。与预期相反，在更高的类似干预的复述密度下，SLI组没有提高其准确性，而TL组的表现明显更差（d = 0.47）。
在对话水平上，复述比单独的模型更有助于动词学习，但仅在TL组中。在这个简短的干预实验中，将复述密度提高到适度水平对SLI儿童没有益处，并且导致TL儿童学习更差。为了优化学习，必须考虑复述分布的效率以及速率。
