The relationship between mean length of utterance (MLU), Persian developmental sentence score (PDSS), and photographic expressive Persian grammar test (PEGT) in typically developing children and those with developmental language disorder (DLD)

Abstract

Purpose

This study investigated the relationship between three practical measures for evaluating Persian grammar expression skills, MLU, PDSS, and PEGT, in preschool children with developmental language disorder (DLD) and their typically developing (TD) peers.

Method

Secondary data were obtained by re-analyzing language samples collected in previous studies. Previously audiotaped language samples of 25 monolingual 5–7 years-old Persian children with DLD and 25 TD children were transcribed and reanalyzed to calculate MLU in words (MLU-w) and PDSS for comparison with the results of PEGT.

Results

Children with DLD had lower scores in PEGT, PDSS, and MLU-w than TD children (p < 0.001). In addition, there was a strong correlation between PDSS and MLU-w in both DLD (r = 0.91) and TD groups (r = 0.79). There was a significant correlation between PEGT and MLU (r = 0.76) and PDSS (r = 0.78) in the DLD group, while these correlations were not significant in TD group.

Conclusions

Considering the positive and significant correlation between MLU, PDSS, and PEGT in children with DLD, the use of PEGT, as a valid, reliable, and accurate test of grammar, which can be implemented quickly and easily, is suggested for clinical purposes of identification and screening of Persian children with DLD.

Keywords:

• Developmental Language disorders
• child
• Persian
• grammar
• test

Acknowledgment

We want to thank the financial support of the Vice Chancellor for Research and Technology of Mashhad University of Medical Sciences, as well as all the people who helped conduct the study.

Authors’ contribution

Nasrin Shahouzaei (first author), Introduction Author/Assistant Researcher; Toktam Maleki Shahmahmood (Second author), Introduction Author/Statistical Analyst/Methodologist/Discussion Author; Fatemeh Haresabadi (Third author), Introduction Author/Original Researcher/Statistical Analyst/Methodologist/Discussion Author; Nahid Jalilehvand (Fourth author), Statistical Analyst/Methodologist; Zahra Sharifi Movahhed (Fifth author), Assistant Researcher.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated during and analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This article was extracted from a research project and was supported by Mashhad University of Medical Sciences (MUMS) [grant NO. 992379].