WHAT IS DYSLEXIA?

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The journey to a new definition of dyslexia:

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The Dyslexia Delphi Study was designed to bring together a wide range of experts to agree on key aspects of how dyslexia should be defined, and to reduce confusion and misinformation around the term. The findings from this work have been published in peer‑reviewed journals, including the Journal of Child Psychology and Psychiatry and the journal Dyslexia (Carroll et al., 2025; Holden et al., 2025).

Importantly, the new Delphi definition reflects the same core cognitive characteristics highlighted in the earlier Rose (2009) definition, while also emphasising the impact dyslexia can have on individuals. This means that people who were previously identified as dyslexic under the Rose definition would still be expected to meet the criteria under the new Delphi definition.

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Delphi definition of dyslexia
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 all languages, difficulties in reading fluency and spelling are key markers 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.

 

Indicators in the Early Years:

• Sequencing difficulties eg visual patterns

• Late speech development/mixed up phrases

• Difficulty remembering known objects e.g. bed, shoe 

• Struggles to learn rhyme e.g. cat/ mat pig/ big

• Confusion between directional words

• Difficulties remembering names of known objects

• Enjoys being read to but shows little interest in letters or words

• Difficulties learning/ clapping a simple rhyme/syllables

• Coordination difficulties

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Indicators in Primary School Aged Children:

• Difficulties with reading or spelling

• Writes letters and numbers the wrong way round e.g. b/d

• Reads a word but will not recognise it further down on the page

• Spells words several different ways in one piece of writing

• Poor concentration for reading and spelling

• Difficulties with time and tense

• Has difficulty recognising sounds in words/poor sense of rhyme

• Poor standard of written work compared to oral ability

• Leaves letters out of words and/or writes them in the wrong order

• Problems processing language at speed- needs instructions repeated

• Areas of strength in other subjects

• Poor confidence and self-esteem

• Difficulties following instructions

• Poor organisational skills

• Handwriting difficulties.

• Sequencing difficulties e.g. days of week and months of the year

• Confusion with left and right

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Indicators in Children 12 and above: 

• Continues to find reading a challenge

• Spelling and Reading inaccuracies 

• Slow to process input and instructions - needs to be repeated

• Confuses  times, places and dates

• Poor organisational skills

• Difficulties planning, organising, sequencing ideas and writing essays

• Difficulties processing complex language

• Difficulties with note toking  or copying from board

• Word finding difficulties.

 

Dyslexia and Maths:

Dyslexia can have an impact on mathematical ability and can be seen in the following ways:

• Answering words problems  due to reading difficulties

• Short-term /working memory difficulties can affect a learner’s ability to remember methods, develop automaticity and complete mental arithmetic

• Slow processing speed - impacting a learner’s ability to keep up with the pace in lessons which results in missing input and a lack of understanding

• Difficulties with sequencing and logic skills - affecting ability to recognise patterns and follow procedures

• May learn by rote but will not understand the overall  concept e.g. multiplication tables

• May have perception difficulties and will find it difficult to interpret diagrams

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