Pattern-Based Target Selection for Treatment of Irregular Past Tense: A Single-Case Experimental Design for Children With Developmental Language Disorder

Purpose: Many children with developmental language disorder (DLD) demonstrate difficulty inflecting irregular past tense verbs. We evaluated using phonological-based patterns (i.e., schemas) to select targets for treatment of irregular verb inflection for children with DLD. We hypothesized this approach would result in acquisition of treated verbs, generalization to untreated verbs within the same phonological schema, and increased use of correct irregular verbs in naturalistic contexts. Method: Treatment was provided to three 7-year-old participants with DLD in the context of multiple baseline designs across behaviors and participants. Phonological schemas included vowel change, final alveolar, and dual change irregular verbs. Treatment was provided using established therapeutic approaches, including narrative generation, sentence imitation, and naturalistic play activities. Acquisition of treated and untreated targets was assessed at the beginning of sessions, and use of verbs in naturalistic contexts was observed throughout treatment sessions. Results: Positive acquisition effects were noted for two of three participants. Generalization to untreated items occurred within and across treatment sets for two participants, whereas increases in accurate irregular verb production in naturalistic contexts were not observed. Conclusions: Outcomes demonstrated support for a pattern-based approach to target selection for treatment of irregular past tense verbs. One participant, who demonstrated general difficulty with the probe and treatment tasks, showed no treatment effect, suggesting that the treatment may be effective for some children with DLD. Further research is warranted to determine what factors might have influenced these variable outcomes across participants.