Measuring word complexity in speech screening: single-word sampling to identify phonological delay/disorder in preschool children

Background: Children's speech sound development is assessed by comparing speech production with the typical development of speech sounds based on a child's age and developmental profile. One widely used method of sampling is to elicit a single-word sample along with connected speech. Words produced spontaneously rather than imitated may give a more accurate indication of a child's speech development. A published word complexity measure can be used to score later-developing speech sounds and more complex word patterns. There is a need for a screening word list that is quick to administer and reliably differentiates children with typically developing speech from children with patterns of delayed/disordered speech. Aims: To identify a short word list based on word complexity that could be spontaneously named by most typically developing children aged 3;005;05 years. Methods & Procedures: One hundred and five children aged between 3;00 and 5;05 years from three local authority nursery schools took part in the study. Items from a published speech assessment were modified and extended to include a range of phonemic targets in different word positions in 78 monosyllabic and polysyllabic words. The 78 words were ranked both by phonemic/phonetic complexity as measured by word complexity and by ease of spontaneous production. Outcome & Results: The ten most complex words (hereafter Triage 10) were named spontaneously by more than 90% of the children. There was no significant difference between the complexity measures for five identified age groups when the data were examined in 6-month groups. A qualitative analysis revealed eight children with profiles of phonological delay or disorder. When these children were considered separately, there was a statistically significant difference (p < 0.005) between the mean word complexity measure of the group compared with the mean for the remaining children in all other age groups. The Triage 10 words reliably differentiated children with typically developing speech from those with delayed or disordered speech patterns. Conclusions & Implications: The Triage 10 words can be used as a screening tool for triage and general assessment and have the potential to monitor progress during intervention. Further testing is being undertaken to establish reliability with children referred to speech and language therapy services.