Approximately 8% of preschool students have speech and language difficulties. A significant portion of these preschool students will present with a diagnosis of a primary speech and language disorder. This single subject research study investigated the effectiveness of the Developmental Language Preschool Therapy Approach (DLPTA) for students identified with receptive and expressive language disorders, specifically measuring the participants’ progress in the areas of rate of spontaneous verbalizations, utterance length (e.g., mean length of utterance), and expressive vocabulary growth (e.g., Type Token Ratio). In this A-B design, 20 sessions of DLPTA were provided to three preschool participants, ranging from 3-years, 4 months to 4years, 4-months old, with a mixed receptive-expressive language disorder. Results indicated that the DLPTA indicated statistically and clinically significant increases in spontaneous verbalizations and mean length of utterance (e.g., phrase length) for Participants One, Two and Three. The DLPTA indicated a clinically significant impact on Type Token Ratio for Participants One, Two and Three. In addition, increases were noted in the total number of different words and total number of words that Participants One, Two and Three used. Additionally, expansions were noted in the grammatical tenses, question asking and use of wh-words used by all three participants. Qualitatively, parents reported a decrease in participant tantrum behavior and parent frustration and increases in the ability to understand their child, engage in a reciprocal conversation, and an increase in quality of life due to the DLPTA.
