Exemplar variability facilitates retention of word learning by children with specific language impairment

Purpose: Variability in the input plays an important role in language learning. The current study examined the role of object variability for new word learning by preschoolers with specific language impairment (SLI). Method: Eighteen 4- and 5-year-old children with SLI were taught 8 new words in 3 short activities over the course of 3 sessions. Half of the children saw 3 identical objects corresponding to each new word during training (No Variability group); the other half of the children saw 3 different objects corresponding to each new word during training (High Variability group). Children completed vocabulary learning tests for objects seen during training and for new within-category objects that were never seen during training as a test of category generalization. Learning was assessed the day after each training activity, and retention was assessed 3 weeks after the last training session. Results: There were no group differences on trained or generalization items immediately following training sessions. However, children in the High Variability group demonstrated significantly better retention 3 weeks after experimental training. Conclusion: These findings demonstrate that object variability facilitates retention of new word learning by children with SLI.