The applicability of D, MTLD, and MATTR in Mandarin–speaking children.

Highlights • Typically developing children had higher D , MTLD, and MATTR than children with language delay. • 4-year-olds produced significantly higher D and MTLD than the 3-year-olds. • D and MTLD showed strong sensitivity in assessing Mandarin-speaking children. Abstract Purpose The purpose of this study is to evaluate the applicability of D , the Measure of Textual Lexical Diversity (MTLD), and Moving ¬Average Type ¬Token Ratio (MATTR) for measuring lexical diversity of Mandarin-speaking preschoolers. This study examined if D , MTLD, and MATTR can be used to differentiate two different age groups (children age 3 and 4 years) and two language ability groups (typically developing children and children with language delay). Method Seventy-eight Mandarin-speaking typically developing children and 56 Mandarin-speaking children with language delay participated in this study. The researchers collected, transcribed, and analyzed language samples from these children. Results The findings showed that D and MTLD were sensitive LD measures for assessing the Mandarin-speaking preschoolers. D and MTLD differentiated the two different age groups and language ability groups. The D and MTLD scores of typically developing children were significantly higher than those of children with language delay. Also, 4-year-olds had significantly higher D and MTLD scores than 3-year-olds. MATTR differentiated the two language ability groups but not the two age groups. Possible factors influencing the sensitivity of lexical diversity measures were discussed. Conclusions The findings indicated that D and MTLD were sensitive for assessing Mandarin-speaking preschoolers from Taiwan. MATTR can be used to identify children with language delay in this study. [ABSTRACT FROM AUTHOR]