Studies have shown that variability (using a mix of different examples) can improve vocabulary and grammar learning for preschoolers with Developmental Language Disorder (DLD). In this study, Nicholas and colleagues wanted to find out if variability also helped children learn prepositions.
Two prepositions, above and beside, were targeted in the study; the children didn’t know those words before the training began. The researchers controlled the variability of both (1) the objects presented to the children to demonstrate the meaning of the prepositions, and (2) the labels the clinicians used for those objects:
There were 3 groups. In each group, one morpheme was taught with low variability and the other was taught with high variability over three short sessions:
Typically developing children, high/low object and label variability
Typically developing children, high/low object variability only
Children with DLD, high/low object variability only
This was an early, exploratory study using a series of cases, so the results are a little tricky to interpret. In the first group, half of the typically developing children showed a benefit for low object and label variability (e.g., This is above that, demonstrated with similar objects). In the second group, 4 of 6 typically developing children showed a benefit for high object variability (e.g., This is above that, demonstrated with different objects). Results for children with DLD in the third group were more mixed. Four children did better when objects had low variability, but two children did better with high object variability. Overall, children with higher language skills seemed to benefit more from label variability, and children with higher receptive vocabulary seemed to benefit more from object variability.
So what does this mean for practice? If you’re working with a child who has low overall language or receptive vocabulary skills, trying to show the meaning of a preposition with a bunch of different words and objects might be confusing or distracting. Instead, you might limit the variety of the objects you use to show what it means, as well as what you call them.
Nicholas, K., Alt, M., & Hauwiller, E. (2019). Variability of input in preposition learning by preschoolers with developmental language disorder and typically-developing language. Child Language Teaching and Therapy. doi:10.1177/0265659019830455