An Investigation to Validate the Grammar and Phonology Screening (GAPS) Test to Identify Children with Specific Language Impairment

BACKGROUND The extraordinarily high incidence of grammatical language impairments in developmental disorders suggests that this uniquely human cognitive function is "fragile". Yet our understanding of the neurobiology of grammatical impairments is limited. Furthermore, there is no "gold-standard" to identify grammatical impairments and routine screening is not undertaken. An accurate screening test to identify grammatical abilities would serve the research, health and education communities, further our understanding of developmental disorders, and identify children who need remediation, many of whom are currently un-diagnosed. A potential realistic screening tool that could be widely administered is the Grammar and Phonology Screening (GAPS) test--a 10 minute test that can be administered by professionals and non-professionals alike. Here we provide a further step in evaluating the validity and accuracy (sensitivity and specificity) of the GAPS test in identifying children who have Specific Language Impairment (SLI). METHODS AND FINDINGS We tested three groups of children; two groups aged 3;6-6:6, a typically developing (n = 30) group, and a group diagnosed with SLI: (n = 11) (Young (Y)-SLI), and a further group aged 6;9-8;11 with SLI (Older (O)-SLI) (n = 10) who were above the test age norms. We employed a battery of language assessments including the GAPS test to assess the children's language abilities. For Y-SLI children, analyses revealed a sensitivity and specificity at the 5(th) and 10(th) percentile of 1.00 and 0.98, respectively, and for O-SLI children at the 10(th) and 15(th) percentile .83 and .90, respectively. CONCLUSIONS The findings reveal that the GAPS is highly accurate in identifying impaired vs. non-impaired children up to 6;8 years, and has moderate-to-high accuracy up to 9 years. The results indicate that GAPS is a realistic tool for the early identification of grammatical abilities and impairment in young children. A larger investigation is warranted in children with SLI and other developmental disorders.