Bound-morpheme generalization by children with SLI: is there a functional relationship with accuracy of response to training targets?

We investigated whether limited bound-morpheme generalization (BMG) by preschool children with SLI is functionally related to limited learning of training targets (words, affixed forms). Thirty children with SLI and 30 age-/gender-matched controls participated in the study. Production probes revealed a dissociation between learning and generalization performance. In addition, the number of children who achieved criterion-level BMG increased abruptly during an additional instructional experience with new training targets. These findings suggest that positive evidence of a bound morpheme's generalizability to different vocabulary stems benefits BMG. Furthermore, they suggest that limited BMG reflects problems not with the storage or access of specific trained facts but with the extraction and extension of the linguistic pattern (e.g., regularity, "rule") instantiated in the learning targets.