For decades, the definition of dyslexia has been the subject of controversy, with different diagnostic criteria used across different countries. This has caused confusion for professionals and parents alike, and an urgent need to review the definition.
The Delphi Definition comes into play, a new definition for dyslexia with an emphasis on processing skills and fluency.
What is the definition for dyslexia?
Nature
The nature and developmental trajectory of dyslexia depends 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). impact of dyslexia.
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 fluency and spelling are a key marker of
dyslexia.
Variance and co-occurrence
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.
Carroll, J., Holden, C., Kirby, P., Snowling, M. J., & Thompson, P.A. (2025) Journal
of Child Psychology and Psychiatry.
What does the new definition of dyslexia mean for your child?
This new definition brings clarity. It distinguishes between age-related learning delays and genuine cognitive impairments – meaning that assessments are more accurate and timely.
New guidance on Dyslexia Assessment Age
It also prompted a review of the dyslexia assessment age. Previously, dyslexia assessments could be carried out at any age, but now we will be waiting until a child is 8 years or older. This allows time for literacy skills to develop naturally and reduces the risk of misdiagnosis.
For children under 8, a literacy assessment may be more appropriate, pinpointing the areas of difficulty earlier and allowing time to get support and interventions in place to aid the child’s developmental stage.
By age 10 most children are preparing for their SATs or 11 Plus. A clear diagnosis will put the appropriate access arrangements in place, so they’ll be better prepared for their SATs or 11 Plus and enable them to demonstrate their true knowledge.
Early signs of dyslexia in primary school children
Dyslexia is a neurological issue which affects the way the brain processes information. This means that anyone with dyslexia can have difficulty processing and remembering information.
Every child is unique, but early signs may include
• Difficulty with phonics and rhyming
• Struggles with letter recognition
• Family history of dyslexia (see blog – Is Dyslexia Genetic?)
However the new definition recognises that these areas could be a delay in a child’s learning development and not necessarily dyslexia.
This gives space for professionals to give children under 8 a literacy assessment in place of a dyslexia assessment – to avoid any risk of misdiagnosis and placing interventions early that will help develop their needs.
About Dyslexia First
Dyslexia First provides first-class dyslexia assessments for children and adults across the North West.
Owner Michala Morton has worked in the field of Special Needs for over 20 years, across a wide range of educational settings, and works closely with The British Dyslexia Association and The Dyslexia Association assessing children and adults.
Based in Newton-le-Willows, Merseyside, Dyslexia First is conveniently accessible by train, linking to Central Liverpool, Manchester and cities within an hour’s commute.
If you’re concerned about your child’s progress, Dyslexia First offers first-class assessments tailored to age and need. We’re here to help you navigate the journey with clarity, compassion, and confidence.
By helping you to get the right support, a world of possibilities will open, that might not have seemed accessible before.
Contact us to discuss your assessment needs at michala@dyslexia-first.co.uk or call 07711 904 589.
Our Top 8 Educational Games for Dyslexic Children
Our top 8 educational games for dyslexic kids give another route to overcoming classroom barriers. During a child’s school years, the struggle with dyslexia becomes
Raising the Volume on Dyslexia: Why Recognition in Schools Matters
As a dyslexia assessor, I meet students who’ve spent years believing they’re “just not good at school.” By the time they reach me, many have
Starting Strong: Supporting A Dyslexic Child in the First Month of Term
Supporting a dyslexic child in school
The first month of a new school term can feel overwhelming for any child. Whether they’re experiencing their very first day of school or returning to a new year. For a dyslexic learner, it often comes with added layers of anxiety and uncertainty.
