Word learning by children with developmental language disorder: Identifying gaps in our understanding of spaced retrieval effects.

Background and aims: Current evidence shows that children with developmental language disorder (DLD) benefit from spaced retrieval during word learning activities. Word recall is quite good relative to recall with alternative word learning procedures. However, recall on an absolute basis can be improved further; many studies report that fewer than two-thirds of the words are learned, even with the assistance of spaced retrieval during the learning activities. In this article we identify details of spaced retrieval that are less well understood in an effort to promote more effective learning through retrieval practice. Main contribution: We discuss the importance of factors such as: (a) integrating immediate retrieval with spaced retrieval trials; (b) determining whether gradual increases in spacing have more than short-term benefits relative to equal spacing; (c) discovering the number of successful retrievals sufficient to ensure later recall; (d) using spaced retrieval to avoid erosion of phonetic details on later recall tests; and (e) whether the well-documented difficulties with learning word forms might be tied to a particular subgroup of children with DLD. We also speculate on some of the possible reasons why spaced retrieval is beneficial in the first place. Conclusions: Although many children with DLD make gains in word learning through procedures that incorporate spaced retrieval, there are numerous details involved in the process that can alter its success. Until we have a better understanding of the boundaries of spaced retrieval's effectiveness, we will not be taking full advantage of this promising addition to word learning procedures. Implications: Spaced retrieval activities can be an important addition to the resources that clinicians and educators have available to assist children in their word learning. With a deeper understanding of the issues discussed here, we should be able to put spaced retrieval to even greater use.