The purpose of this study was to investigate the role of variability in teaching prepositions to preschoolers with typical development (TD) and developmental language disorder (DLD). Input variability during teaching can enhance learning, but is target dependent. We hypothesized that high variability of objects would improve preposition learning. We also examined other characteristics (e.g. vocabulary skills) of children who responded to treatment. We used a case series design, repeated across children (n = 18) to contrast how preschoolers learned prepositions in conditions that manipulated variability of objects and labels across three treatment sessions. We contrasted a high versus low variability condition for objects and labels for one group of typically-developing (TD) children (n = 6). In other groups (TD, n = 6; DLD, n = 6), we contrasted high versus low object variability only. Visual inspection and descriptive statistics were used to characterize gains. Half (n = 3) of TD participants showed a low variability advantage for the condition that combined object and label variability. In the condition that only contrasted object variability, the majority (n = 4) of TD participants showed a high variability advantage, compared to only two participants with DLD. In the high object variability condition, high receptive vocabulary scores were significantly correlated with high performance of learning prepositions (rs = 0.71, p < 0.05). Combining high variability for objects and labels when teaching prepositions was not effective. However, high variability for objects can create a learning advantage for learning prepositions for children with typically developing language, but not all learners. Characteristics of different learners (e.g. receptive vocabulary scores) and language status (impaired or unimpaired) should be taken into consideration for future studies.

中文翻译：

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发育性语言障碍和典型发育语言学龄前儿童介词学习输入的变异性

本研究的目的是调查变异在向具有典型发育 (TD) 和发育性语言障碍 (DLD) 的学龄前儿童教授介词中的作用。教学过程中的输入可变性可以增强学习，但取决于目标。我们假设对象的高度可变性会改善介词学习。我们还检查了对治疗有反应的儿童的其他特征（例如词汇技能）。我们使用案例系列设计，在儿童 (n = 18) 中重复，以对比学龄前儿童如何在三个治疗过程中操纵对象和标签可变性的条件下学习介词。我们对比了一组典型发育 (TD) 儿童 (n = 6) 的对象和标签的高与低可变性条件。在其他组中（TD，n = 6；DLD，n = 6），我们仅对比了高与低对象可变性。视觉检查和描述性统计用于表征增益。一半 (n = 3) 的 TD 参与者在结合对象和标签可变性的条件下表现出低可变性优势。在仅对比对象可变性的情况下，与只有两名 DLD 参与者相比，大多数 (n = 4) TD 参与者表现出高可变性优势。在高对象可变性条件下，高接受词汇分数与学习介词的高性能显着相关（rs = 0.71，p < 0.05）。在教授介词时结合对象和标签的高度可变性是无效的。然而，物体的高度可变性可以为具有典型语言发育的儿童学习介词创造学习优势，但并非所有学习者。未来的研究应考虑不同学习者的特征（例如接受性词汇分数）和语言状态（受损或未受损）。