Vocabulary Diversity in Personal Narratives Produced in Response to the Global TALES Protocol in Dutch-Speaking Students with and without Dyslexia.

Introduction: This study examines whether there are differences in expressive vocabulary between participants with and without dyslexia in personal narratives in response to the Global TALES protocol.

Methods: 22 monolingual Dutch-speaking participants aged 11-16 with dyslexia and 22 age and gender-matched peers without dyslexia were assessed on measures of decoding, reading comprehension, and spelling of words, pseudowords, verbs, and sentences. The participants also produced personal narratives in response to the six prompts contained in the Global TALES protocol. We analyzed the personal narratives for expressive vocabulary and counted the total number of different words (TNDW).

Results: The study revealed a significant relationship between TNDW and reading comprehension (r = 0.45, p = 0.002, BF10 = 17.70), spelling words (r = 0.42, p = 0.005, BF10 = 8.93), and spelling and writing conventions in sentences (r = 0.37, p = 0.016, BF10 = 3.11). The Global TALES protocol was successful in eliciting personal narratives in the Dutch-speaking participants with and without dyslexia. Participants with dyslexia used fewer different words (M = 192.27, SD = 64.37; 95% CI: [151.84-232.71]) compared to peers without dyslexia (M = 265.50, SD = 116.28; 95% CI: [225.06-305.93]; F(1, 42) = 6.68; p = 0.013; η2 = 0.14). When we compared the probability of models, Bayesian factors revealed moderate evidence for group differences in TNDW (BF = 3.94).

Conclusion: Our findings indicate that older school-age participants with dyslexia may lag behind their peers in expressive vocabulary in a personal narrative discourse task that is relevant to everyday functioning. The results of this study highlight the relationship between expressive vocabulary and reading comprehension and the importance of the assessment of spoken language skills in children with dyslexia. Reading problems might lead to less advanced spoken language, which in turn may negatively affect the expressive vocabulary growth in individuals with dyslexia.