Date of Award


Document Type


Degree Name

Master of Science (MS)


Communication Sciences & Disorders

First Advisor

Dr. Sarah Robinson


Speech-language pathologists (SLPs) are urged to make evidence-based treatment decisions, but it is challenging to determine the appropriate intervention intensity for children with speech sound disorders (SSD) due to limited published information. This study is a single subject, multiple baseline design that compares the phonological changes of four preschool children (4;0 to 4;9) who received therapy either twice a week or four times a week for a total of twenty, 50-minute sessions. Each child’s production accuracy of treated sounds and overall percent consonants correct (PCC) values were used to qualitatively and quantitatively measure generalization via raw scores, d scores, and learning rate scores. Daily treatment data and phonemic/cluster inventories were also considered when comparing the children amongst different intensity conditions. The two children treated with a higher dose frequency (4x/week) demonstrated greater levels of phonological change due to treatment than the two children treated with a lower dose frequency (2x/week). This trend was observed across various measurement metrics, including PCC, treatment sound accuracy in untreated words, and changes to phonemic and cluster inventories. An advantage for treatment of a high dose frequency was observed even though the learning curves, which represented sound learning during productions of treatment target words, displayed similar production accuracies between conditions. Thus, traditional treatment provided on an intensive schedule was more efficacious than treatment on a less intensive schedule when considering the system-wide phonological changes following treatment. In other words, an intensive therapy schedule elicited faster and greater phonological change. With a finding such as this and a growing interest for researchers to study the differences in intervention intensity variables, SLPs should begin to reference the current literature when making decisions regarding treatment scheduling for children with SSD.

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Communication Commons