Should We Stop Using Lexical Diversity Measures in Children's Language Sample Analysis?

PURPOSE

Prior work has identified weaknesses in commonly used indices of lexical diversity in spoken language samples, such as type-token ratio (TTR) due to sample size and elicitation variation, we explored whether TTR and other diversity measures, such as number of different words/100 (NDW), vocabulary diversity (VocD), and the moving average TTR would be more sensitive to child age and clinical status (typically developing [TD] or developmental language disorder [DLD]) if samples were obtained from standardized prompts.

METHOD

We utilized archival data from the norming samples of the Test of Narrative Language and the Edmonton Narrative Norms Instrument. We examined lexical diversity and other linguistic properties of the samples, from a total of 1,048 children, ages 4-11 years; 798 of these were considered TD, whereas 250 were categorized as having a language learning disorder.

RESULTS

TTR was the least sensitive to child age or diagnostic group, with good potential to misidentify children with DLD as TD and TD children as having DLD. Growth slopes of NDW were shallow and not very sensitive to diagnostic grouping. The strongest performing measure was VocD. Mean length of utterance, TNW, and verbs/utterance did show both good growth trajectories and ability to distinguish between clinical and typical samples.

CONCLUSIONS

This study, the largest and best controlled to date, re-affirms that TTR should not be used in clinical decision making with children. A second popular measure, NDW, is not measurably stronger in terms of its psychometric properties. Because the most sensitive measure of lexical diversity, VocD, is unlikely to gain popularity because of reliance on computer-assisted analysis, we suggest alternatives for the appraisal of children's expressive vocabulary skill.

Transcription Decisions of Conjoined Independent Clauses Are Equitable Across Dialects but Impact Measurement Outcomes

PURPOSE

Transcription of conjoined independent clauses within language samples varies across professionals. Some transcribe these clauses as two separate utterances, whereas others conjoin them within a single utterance. As an inquiry into equitable practice, we examined rates of conjoined independent clauses produced by children and the impact of separating these clauses within utterances on measures of mean length of utterance (MLU) by a child's English dialect, clinical status, and age.

METHOD

The data were archival and included 246 language samples from children classified by their dialect (African American English or Southern White English) and clinical status (developmental language disorder [DLD] or typically developing [TD]), with those in the TD group further classified by their age (4 years [TD4] or 6 years [TD6]).

RESULTS

Rates of conjoined independent clauses and the impact of these clauses on MLU varied by clinical status (DLD < TD) and age (TD4 < TD6), but not by dialect. Correlations between the rate of conjoined clauses, MLU, and language test scores were also similar across the two dialects.

CONCLUSIONS

Transcription decisions regarding conjoined independent clauses within language samples lead to equitable measurement outcomes across dialects of English. Nevertheless, transcribing conjoined independent clauses as two separate utterances reduces one's ability to detect syntactic differences between children with and without DLD and document syntactic growth as children age.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25822675.

Developmental language disorder in Chinese children: A systematic review of research from 1997 to 2022

Developmental language disorder (DLD) is one of the most common neurodevelopmental disorders. The influences of DLD on language development have been delineated in detail in English. The same is not true for Chinese, a group of Sinitic languages with distinct typological features that may modify the profile of DLD crosslinguistically. We conducted a systematic search of English and Chinese journal databases and reviewed 59 studies on the manifestations of DLD in Chinese. Methodological quality appraisal of the literature revealed several areas of improvement to enhance transparency and replicability. A bibliometric analysis indicated a steep growth trajectory of this literature. Examination of the participant selection and diagnostic criteria revealed limitations and calls for the development of assessment tools and increased knowledge of evidenced-based diagnostic practice. Areas of deficits demonstrated by Chinese children with DLD were synthesized qualitatively and discussed in light of the literature on clinical markers of DLD in English.

Vietnamese children with and without DLD: Classifier use and grammaticality over time

INTRODUCTION

One way to identify Developmental Language Disorder (DLD) is to establish clinical markers in a language to serve as reliable indicators of the disorder. This study embarks on the search for clinical markers for Vietnamese using longitudinal data from children with and without DLD.

METHODS

We matched ten children previously classified with DLD to ten with typical development (TD) by age and gender. Participants completed a story generation task at three time points: kindergarten, first, and second grade. Overall grammatical development was measured using mean length of utterance, MLU, and proportion of grammatical utterances, PGU. We examined a language-specific feature, classifiers, in terms of accuracy (omission errors), diversity (number of different classifiers), and productivity, or the use of classifiers in constructions of two-to-three elements (classifier+noun, numeral+classifier+noun). Longitudinal change and group differences were examined using linear mixed modeling, supplemented by linguistic analysis.

RESULTS

Both groups increased in MLU and PGU over time. The DLD group performed lower in kindergarten and continued to show lower performance over time on these measures. Classifier omission errors decreased over time with no group differences. Classifier diversity increased across groups, with lower performance by the DLD group in kindergarten and over time. For classifier productivity, TD children used classifiers in multiple constructions in kindergarten and maintained the same level over time. In contrast, children with DLD had minimal use of three-element constructions in kindergarten but increased in productivity over time.

CONCLUSIONS

Children with DLD produce shorter utterances with relatively more grammatical errors compared to their TD peers in the early school years. Though no longer committing classifier omission errors, children with DLD showed more restricted use of classifiers in terms of the number of different classifiers and constructions produced. Findings inform the search for Vietnamese clinical markers of DLD.

Sharpening Our Tools: A Systematic Review to Identify Diagnostically Accurate Language Sample Measures

PURPOSE

This systematic review provides a comprehensive summary of the diagnostic accuracy of English language sample analysis (LSA) measures for the identification of developmental language disorder.

METHOD

An electronic database search was conducted to identify English publications reporting empirical data on the diagnostic accuracy of English LSA measures for children aged 3 years or older.

RESULTS

Twenty-eight studies were reviewed. Studies included between 18 and 676 participants ranging in age from 3;0 to 13;6 (years;months). Analyzed measures targeted multiple linguistic domains, and diagnostic accuracy ranged from less than 25% to greater than 90%. Morphosyntax measures achieved the highest accuracy, especially in combination with length measures, and at least one acceptable measure was identified for each 1-year age band up to 10 years old.

CONCLUSION

Several LSA measures or combinations of measures are clinically useful for the identification of developmental language disorder, although more research is needed to replicate findings using rigorous methods and to explore measures that are informative for adolescents and across diverse varieties of English.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21183247.

The Contribution of Socioeconomic Status to Children's Performance on Three Grammatical Measures in the Edmonton Narrative Norms Instrument

Purpose The purpose of this study was to evaluate the relative contribution of socioeconomic status (SES) on three grammatical measures-finite verb morphology composite (FVMC), percent grammatical utterances (PGU), and clausal density-in children between the ages of 4 and 9 years. Method Data for this study were from the normative sample in the Edmonton Narrative Norms Instrument. For 359 children, hierarchical linear regression was performed to evaluate the amount of variance in FVMC, PGU, and clausal density that was uniquely explained by SES after accounting for child chronological age and language status (typical, impaired). Results After child age and language status were controlled, SES was a significant predictor of PGU and clausal density scores, but not of FVMC scores. SES uniquely accounted for 0.5% of variance in PGU scores and 0.8% of variance in clausal density scores. Conclusions Consistent with maturational accounts of children's development of tense markers, results of this study offer evidence that, among grammatical measures, FVMC is uniquely robust to variation in SES. Although significant, the variance of PGU and clausal density scores uniquely accounted for by SES was close to minimum. Clinicians can therefore include these three grammatical measures for assessing children of different socioeconomic backgrounds. Supplemental Material https://doi.org/10.23641/asha.14810484.

Clausal Density Between Ages 4 and 9 Years for the Edmonton Narrative Norms Instrument: Reference Data and Psychometric Properties

Purpose This study provided reference data and examined psychometric properties for clausal density (CD; i.e., number of clauses per utterance) in children between ages 4 and 9 years from the database of the Edmonton Narrative Norms Instrument (ENNI). Method Participants in the ENNI database included 300 children with typical language (TL) and 77 children with language impairment (LI) between the ages of 4;0 (years;months) and 9;11. Narrative samples were collected using a story generation task, in which children were asked to tell stories based on six picture sequences. CD was computed from the narrative samples. The split-half reliability, concurrent criterion validity, and diagnostic accuracy were evaluated for CD by age. Results CD scores increased significantly between ages 4 and 9 years in children with TL and those with LI. Children with TL produced higher CD scores than those with LI at each age level. In addition, the correlation coefficients for the split-half reliability and concurrent criterion validity of CD scores were all significant at each age level, with the magnitude ranging from small to large. The diagnostic accuracy of CD scores, as revealed by sensitivity, specificity, and likelihood ratios, was poor. Conclusions The finding on diagnostic accuracy did not support the use of CD for identifying children with LI between ages 4 and 9 years. However, given the attested reliability and validity for CD, reference data of CD from the ENNI database can be used for evaluating children's difficulties with complex syntax and monitoring their change over time. Supplemental Material https://doi.org/10.23641/asha.13172129.