A comparison of explicit and implicit interventions to teach a novel grammatical marking to children with language impairment

Abstract

Purpose. Most first language intervention approaches rely on implicit techniques to teach problematic language forms to children with language impairment. That is, learners are not made conscious of the patterns guiding language forms at any stage of the intervention process. The language gains made by children using these implicit approaches are modest and require many treatment sessions over a long period of time. Related disciplines, such as second language learning and word reading instruction, have found that explicit instructional approaches in which language patterns are directly presented to learners are more beneficial than implicit approaches similar to those used in child language interventions. This study directly compares the efficacy of explicit and implicit techniques when teaching a novel grammatical marking to children with specific language impairment.

Method. Thirty-two 6-, 7-, and 8-year old children with specific language impairment were randomly assigned to either an implicit or explicit treatment group. Each participant completed four teaching sessions to learn a novel gender agreement morpheme. Participants in the Explicit Group were presented with models of the novel marking plus the rule guiding the form. Participants in the Implicit Group received only models of the novel form. Learning was assessed in three different production probes given during each treatment session.

Results. Significantly more participants in the Explicit Group than the Implicit Group acquired the novel morpheme based on a Teaching Probe and a Generalization Probe (both ps = 0.03, Φs = 0.44 and 0.45, respectively). On a Maintenance Probe a greater number of participants in the Explicit Group acquired the novel morpheme compared to the Implicit Group; however, this difference was marginally significant ( p = 0.05, Φ = 0.41).

Conclusions. A clear advantage was identified for the explicit language teaching approach over the implicit approach in this study. However, there were several limitations to this advantage because treatment gains varied across participants, testing contexts, and sessions. Future studies should continue to examine the efficacy of explicit techniques for children with language impairment when targeting true grammatical morphemes with focus on the generalization of the targeted forms and long-term learning effects.