This exploratory study was designed to evaluate functional language changes during and after treatment with language intervention software. Two children with language impairments received Fast ForWord (FFW; Scientific Learning Corporation, 1997), and two other children received a bundle of intervention programs published by Laureate Learning Systems (LLS). The children received intervention for 1 hour and 40 minutes per day for 20 days (4 weeks). Treatment was delivered according to a multiple-probe design in which one child was enrolled in Fast FFW immediately after a baseline phase. Another child remained in an extended baseline phase before beginning FFW. The design was replicated for the bundle of LLS programs. The children with extended baselines were identical twins. Progress was measured by gains on the Oral and Written Language scales (OWLS) and by visual and mathematical examination of trends for language sample measures.
All four children made clinically significant gains (posttest scores outside the 95% confidence interval of the pretest scores) on the OWLS. Two children who received the LLS software and one child who received FFW software made clinically significant gains on mean length of utterance in morphemes (MLU), but only one child, who received treatment with the LLS software, had fewer grammatical errors after treatment. The three children with improved MLU also produced a higher proportion of utterances with mazes. Measures of language content (percent of response errors) and language use (percentage of assertive utterances) were not informative due to high variability and floor effects. The similarity of the treatment effects (especially in the case of the identical twins) was surprising since FFW and the bundle of LLS programs targeted different levels of language, used different types of auditory stimuli, and were designed to promote different kinds of learning.