• • • • Research Note Validating the Use of Percent Grammatical Utterances for Assessing Mandarin-Speaking Children’s Grammatical Skill: Evidence From 3-Year-Olds Ling-Yu Guo, a,b Ping Lee, c Hsin-jen Hsu, d and Linda Spencer e a Department of Communicative Disorders and Sciences, University at Buffalo, NY b Department of Audiology and Speech-Language Pathology, Asia University, Taichung, Taiwan c Department of Rehabilitation, Chinese Medical University Hsinchu Hospital, Taiwan d Department of Special Education, National Tsing Hua University, Hsinchu, Taiwan e MSSLP Program, Rocky Mountain University of Health Professions, Provo, UT ARTICLE INFO Article History: Received September 11, 2023 Revision received December 10, 2023 Accepted February 7, 2024 Editor-in-Chief: Julie A. Washington Editor: M. Adelaida Restrepo https://doi.org/10.1044/2024_JSLHR-23-00557 Correspondence to Ling-Yu Guo: lingyugu@buffalo.edu. Disclosure: The authors have declared that no competing financial or nonfinancial interests existed at the time of publication. ABSTRACT Purpose: The study examined the use of percent grammatical utterances (PGUs) for assessing grammatical skills in Mandarin-speaking 3-year-old children. Method: Participants were 30 Mandarin-speaking 3-year-olds with typical development. Language samples were collected in two visits for each child using a picture description task. Children were asked to talk about 16 pictures in response to questions and prompts at each visit. Pictures for the language sample collection were identical across the visits. PGUs were computed, and the grammatical errors that children produced in the task were coded and tallied for error types at each visit. Test–retest reliability, split-half reliability, and con- current criterion validity of PGUs were evaluated. Results: The mean PGU level was approximately 78% at Visit 1 and 81% at Visit 2, both of which were significantly below the mastery level (i.e., 90%). The correlation coefficient for test–retest reliability of PGU was large (r = .70, p < .01); the correlation coefficient for split-half reliability was medium at Visit 1 (r = .47, p < .01) and large (r = .65, p < .01) at Visit 2. In addition, the correlation coefficient for concurrent criterion validity of PGU was medium for both visits (rs ≥ .35, ps ≤ .03). The ranking and proportion of each error type were similar between the visits. Conclusion: The initial evidence from psychometric properties suggests that PGU computed from the picture description task is a reliable and valid measure for evaluating grammatical skills in Mandarin-speaking 3-year-old children. Supplemental Material: https://doi.org/10.23641/asha.25395499 Language skills play an important role in scaffolding learning in schools and supporting the development of social relationships for children (Eadie et al., 2021; Schoon et al., 2010). Children with developmental lan- guage disorder (DLD) tend to show poorer academic and psychosocial outcomes than their typical peers (Lindsay & Dockrell, 2012; St Clair et al., 2011). They are also at risk for poorer outcomes for employment and life well-being in adulthood (Conti-Ramsden et al., 2018; Dubois et al., 2020). These long-term adverse effects of DLD highlight the importance of early identification and intervention in clinical practice. Identifying DLD in preschool ages, how- ever, has been challenging (Dollaghan, 2013). To make a DLD diagnosis, clinicians must use a variety of technically sound assessment tools and strategies (Individuals with Disabilities Education Act, 2004). A sig- nificant barrier to identifying preschool children with DLD in Taiwan is the paucity of proper norm-referenced, standardized tests. The normative data for most of the extant tests were over 20 years, and some of the tests Journal of Speech, Language, and Hearing Research Vol. 67 1173–1185 April 2024 Copyright © 2024 American Speech-Language-Hearing Association 1173 Downloaded from: https://pubs.asha.org Ling-Yu Guo on 04/10/2024, Terms of Use: https://pubs.asha.org/pubs/rights_and_permissions