Anne Castles and Genevieve McArthur
UNDERSTANDING DYSLEXIA
When reading fails
to develop normally
• No child will learn to read without appropriate
conditions
• But some children (10 - 15%) fail despite:
– No obvious neurological or sensory impairment
– Supportive environment
• “Dyslexia” or “specific learning disability”
How do we detect this in the
classroom?
Using Response to Intervention
in the diagnosis
• Some of the children at the bottom of the
distribution may be “instructional casualties”
• We can identify these through the Response
to Intervention model:
– Do they respond to intensive intervention?
– Or are they still here…
Reading difficulty or “dyslexia”
Profiles of dyslexia
• As reading involves many processes, would
not expect it always to fail in the same way
• Different profiles depending on which subskill
has not developed normally
• Need to have a model of reading to guide
diagnosis and assessment
Letter-Sound Route
Dictionary Look-Up Route
What is needed for assessment?
• Determine whether a
student is reading at
the level expected for
age
• Test all aspects of
reading, without
over‐testing children
that have no problems!
What is needed for assessment?
1. Test of single word
reading aloud (with
normative data)
– Irregular words (yacht)
What is needed?
1. Test of single word
reading aloud (with
normative data)
– Irregular words (yacht)
2. Test of nonword reading
aloud
What is needed for assessment?
1. Test of single word
reading aloud (with
normative data)
– Irregular words
(yacht)
2. Test of nonword
reading aloud
3. Test of Reading
Comprehension
What is needed for assessment?
• Based on these results
can then “drill down”
further
• Use as a basis for a
targeted treatment
Motif.org.au
1. Test of single word reading
• Castles and Coltheart 2
• Set of 40 regular, irregular and non-words
– Each scored separately
• Stopping rule
• Normed on 1000 Australian children yrs 1-6
Motif.org.au
2. Test of Reading Comprehension
• TERC: Test of Everyday Reading Comprehension
• 10 everyday reading tasks increasing in difficulty
– Text screen
– Canteen menu
– Shopping list
• Each followed by two comprehension questions
• Two forms (A and B)
Motif.org.au
Intervention
Intervention
Phonics
• Ability to learn new words using the
“letter‐sound” rules
• SHIP
“sh” “i” “p”
“ship”
• Systematic review and meta-analyses
– Ehri et al. (2000)
– Suggate (2010)
– McArthur, Castles et al. (2012)
• Moderate to large significant effects on poor
phonics skills
Intervention
Intervention
Sight word training
• Ability to learn to recognise whole words by sight
• Particularly important for words that break lettersound rules
• YACHT  “y” “a” “ch” “t”  “yacht” 
• YACHT  “y” “o” “t” “yot” 
• Two controlled trials of sight word training on poor
readers
– McArthur, Castles et al. (2013)
– McArthur, Castles et al. (in preparation)
• Large and significant effects on poor sight word
accuracy
Intervention
Intervention
Language training
• Knowing the meaning of words and how they are
said are spoken language skills that are used
during reading
• Evidence that spoken language training has
moderate to large effects on phonological and
expressive language skills
– Law et al. (2004)
– Cirrin & Gillam (2008)
– Ebbels (2014)
• Spoken language training is typically carried out
by speech and language therapists
Intervention
Commercial Interventions
Evidence based decisions
• Teach teachers how to make evidence‐based decision
about any intervention for poor readers (easier than it
sounds)
• Provide online site that provides evidence-based decisions
(and evidence) for interventions for poor readers (even
easier)
• Inspire teachers to choose evidence-based interventions
– Provide funding for evidence-based interventions on online site
– Schools provide scientific evidence for an intervention to get
funding
– This intervention and evidence added to above online site