Assessment of Childhood Apraxia of Speech: A Review/Tutorial of Objective Measurement Techniques.

Background With respect to the clinical criteria for diagnosing childhood apraxia of speech (commonly defined as a disorder of speech motor planning and/or programming), research has made important progress in recent years. Three segmental and suprasegmental speech characteristics-error inconsistency, lengthened and disrupted coarticulation, and inappropriate prosody-have gained wide acceptance in the literature for purposes of participant selection. However, little research has sought to empirically test the diagnostic validity of these features. One major obstacle to such empirical study is the fact that none of these features is stated in operationalized terms. Purpose This tutorial provides a structured overview of perceptual, acoustic, and articulatory measurement procedures that have been used or could be used to operationalize and assess these 3 core characteristics. Methodological details are reviewed for each procedure, along with a short overview of research results reported in the literature. Conclusion The 3 types of measurement procedures should be seen as complementary. Some characteristics are better suited to be described at the perceptual level (especially phonemic errors and prosody), others at the acoustic level (especially phonetic distortions, coarticulation, and prosody), and still others at the kinematic level (especially coarticulation, stability, and gestural coordination). The type of data collected determines, to a large extent, the interpretation that can be given regarding the underlying deficit. Comprehensive studies are needed that include more than 1 diagnostic feature and more than 1 type of measurement procedure.

The assessment of fidelity in a motor speech-treatment approach.

OBJECTIVE: To demonstrate the application of the constructs of treatment fidelity for research and clinical practice for motor speech disorders, using the Prompts for Restructuring Oral Muscular Phonetic Targets (PROMPT) Fidelity Measure (PFM). Treatment fidelity refers to a set of procedures used to monitor and improve the validity and reliability of behavioral intervention. While the concept of treatment fidelity has been emphasized in medical and allied health sciences, documentation of procedures for the systematic evaluation of treatment fidelity in Speech-Language Pathology is sparse. METHODS: The development and iterative process to improve the PFM, is discussed. Further, the PFM is evaluated against recommended measurement strategies documented in the literature. This includes evaluating the appropriateness of goals and objectives; and the training of speech-language pathologists, using direct and indirect procedures. Three expert raters scored the PFM to examine inter-rater reliability. RESULTS: Three raters, blinded to each other's scores, completed fidelity ratings on three separate occasions. Inter-rater reliability, using Krippendorff's Alpha, was >80% for the PFM on the final scoring occasion. This indicates strong inter-rater reliability. CONCLUSION: The development of fidelity measures for the training of service providers and treatment delivery is important in specialized treatment approaches where certain 'active ingredients' (e.g. specific treatment targets and therapeutic techniques) must be present in order for treatment to be effective. The PFM reflects evidence-based practice by integrating treatment delivery and clinical skill as a single quantifiable metric. PFM enables researchers and clinicians to objectively measure treatment outcomes within the PROMPT approach.