What is dyslexia?
The word ‘dyslexia’ comes from the Greek ‘dys’ meaning ‘difficulty with’ and ‘lexis’ meaning ‘word’ or ‘language’. So ‘dyslexia’ means literally ‘difficulty with words’.
Devon uses the Delphi Definition of Dyslexia (2025), a research-informed definition developed through a collaboration between the University of Birmingham, the SpLD Assessment Standards Committee (SASC), King’s College London, and the University of Oxford. Researchers brought together 58 international experts in dyslexia, including academics, specialist teachers, educational psychologists, and individuals with lived experience of dyslexia.
The Delphi Definition of Dyslexia (2025)
- Dyslexia is a set of processing difficulties that affect the acquisition of reading and spelling.
- In dyslexia, some or all aspects of literacy attainment are weak in relation to age, standard teaching and instruction, and level of other attainments.
- Across languages and age groups, difficulties in reading fluency and spelling are a key marker of dyslexia.
- Dyslexic difficulties exist on a continuum and can be experienced to various degrees of severity.
- The nature and developmental trajectory of dyslexia depends on multiple genetic and environmental influences.
- Dyslexia can affect the acquisition of other skills, such as mathematics, reading comprehension or learning another language.
- The most commonly observed cognitive impairment in dyslexia is a difficulty in phonological processing (i.e. in phonological awareness, phonological processing speed or phonological memory). However, phonological difficulties do not fully explain the variability that is observed.
- Working memory, processing speed and orthographic skills can contribute to the impact of dyslexia.
- Dyslexia frequently co-occurs with one or more other developmental difficulties, including developmental language disorder, dyscalculia, ADHD, and developmental coordination disorder.
Caroll, J. M., Holden, C., Kirby, P., Thompson, P. A. Snowling, M.J., & Dyslexia Delphi Panel (2025) Towards a Consensus on Dyslexia: findings of a Delphi Study. Journal of Child Psychology and Psychiatry, 0(0). 1-12
Nature
- The nature and developmental trajectory of dyslexia depend on multiple genetic and environmental influences.
Manifestation
- Dyslexia is a set of processing difficulties that affect the acquisition of reading and spelling.
- The most commonly observed cognitive impairment in dyslexia is a difficulty in phonological processing (i.e. in phonological awareness, phonological processing speed or phonological memory). However, phonological difficulties do not fully explain the variability that is observed.
- Working memory, processing speed and orthographic skills can contribute to the impact of dyslexia.
Impact
- In dyslexia, some or all aspects of literacy attainment are weak in relation to age, standard teaching and instruction, and level of other attainments.
- Across languages and age groups, difficulties in reading and spelling fluency are a key marker of Dyslexia.
- Dyslexic difficulties exist on a continuum and can be experienced to various degrees of severity.
- Dyslexia can affect the acquisition of other skills, such as mathematics, reading comprehension or learning another language.
- Dyslexia frequently co-occurs with one or more other developmental difficulties, including developmental language disorder, dyscalculia, ADHD and developmental coordination disorder.
Where can I find out more?
If you want to know more about this complex area, the following websites provide more information:
British Dyslexia Association
www.bdadyslexia.org.uk/dyslexia/about-dyslexia
Dyslexia Action
The Dyslexia-SpLD Trust
www.thedyslexia-spldtrust.org.uk/
PATOSS
Professional Association for Teachers of Students with Specific Learning Difficulties
As a Service, we feel that what is most important is that we will seek to identify a student’s specific areas of difficulty and then aim to support the school in addressing the pupil’s specific needs.
www.devon.gov.uk/support-schools-settings/send/areas-of-need/cognition-and-learning/devon-spld/
or contact
rebecca.hughes@qe.devon.sch.uk