Optimally efficient and effective intervention for children with speech sound disorder (SSD) is increasingly shown to depend on the delivery of approaches that map clearly to the sub-type of the child’s SSD and follow the evidence-base with fidelity (e.g., Crosbie et al. 2005, Lousada et al. 2013) in contrast to the eclectic approach favoured by most Speech and Language Therapists (e.g., Hegarty et al. 2020).