Purpose: In the present study, we conducted a systematic review to investigate the core features of the definition of dyslexia across different disciplines according to their associated professional organizations and published research in order to evaluate the presence and type of inconsistencies within and across disciplines in how dyslexia is defined. Method: Definition statements of dyslexia from professional organizations in medicine, education, speech-language pathology, psychology, and the International Dyslexia Association were collected via scope of practice guidelines or via the organization's official website. Using a database with a wide disciplinary reach, we collected 764 of the most cited articles from 2000-2020 with subjects that were children formally identified with dyslexia. We created a coding scheme to examine specific core features of each article and professional organization's definition of dyslexia. We completed data analysis regarding the core features of definitions per organization and journal article discipline. Results: We report descriptive results for dyslexia definition statements from professional organizations and the collected articles. Chi-square tests of independence were conducted between each of the identified core features and professional discipline. We find statistically significant consistencies and inconsistencies in how the definition of dyslexia is reported across disciplines journals. Core features of dyslexia that are reported differently across disciplines include: neurobiological, genetic, normal intelligence, reading disorder, unrelated to environmental influences, word reading deficits, and visual processing deficits. Core features of dyslexia that are equally included as a characteristic of dyslexia are phonological deficits and that dyslexia is a learning disability. Core features that are equally not included as a characteristic of dyslexia included a spelling deficit, need for an IQ discrepancy, that dyslexia is a language-based disorder, or motor processing deficit. Conclusion: Although this study confirms the presence of some inconsistencies in the core features of how dyslexia is defined across different disciplines, other encouraging consistencies were found. Namely, across all disciplines researchers appear to acknowledge that dyslexia is a phonological deficit that doesn't require the presence of an IQ discrepancy. Future work should further analyze the specific diagnostic criteria used to classify children with dyslexia and whether such criteria vary across disciplines.



College and Department

David O. McKay School of Education; Communication Disorders



Date Submitted


Document Type





dyslexia, children, dyslexic, definition, diagnostic criteria



Included in

Communication Commons