Diagnosing Learning Disabilities
Models to diagnose
Reading Disorder
By: Mike Hogan, Chris Franz, &
Ron Teffaine
Canadian Definition of Learning
Disabilities (January 30, 2002)
Learning Disabilities (LDs)… affect… individuals… [with] at least
average abilities… As such, LDs are distinct from global
intellectual deficiency.
LDs result from impairments in one or more processes related to
perceiving, thinking, remembering or learning (e.g., language
processing, phonological processing, processing speed, memory
& attention, executive functions, etc.).
LDs interfere with (1) oral language, (2) reading, (3) written
language, and (4) mathematics.
LDs are lifelong… [They] are suggested by unexpected academic
under-achievement.
LDs are due to genetic and/or neurobiological factors or injury that
alters brain functioning…
DSM-IV-TR LD Model (1994/2000)
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Learning Disorders are diagnosed when:
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an individual’s achievement in reading,
mathematics, or written expression is substantially
below that expected for age, schooling, and level of
intelligence (e.g., ≥ 1½ SDs below the mean).
the learning problems significantly interfere with
academic achievement or activities of daily living
that require reading, math, or writing skills.
DSM-IV-TR LD Model
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Associated Features & Disorders:
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Abnormalities in cognitive processing (e.g., visual
perception, linguistic processes, attention, memory,
etc.)
Medical conditions: lead poisoning, fetal alcohol
syndrome, fragile X syndrome
Demoralization, low self-esteem, social skills deficits,
increased drop-out rate (1.5 times > average)
Higher rate of Disruptive Behaviour & Mood Disorders
DSM-IV-TR LD Model
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Differential Diagnosis
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LDs must be differentiated from:
Normal variations in achievement (< 1 SD below
mean)
 Lack of opportunity (e.g., poor attendance)
 Poor teaching (e.g., home schooling)
 Cultural factors (e.g., EAL)
 Impaired vision or hearing
 Mental retardation (except Mild cases)
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DSM-IV-TR Reading Disorder
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Diagnostic Criteria:
A. Reading achievement (via individually administered
standardized tests of reading accuracy, speed, or
comprehension), is substantially below that expected given
the person’s age, measured intelligence, and ageappropriate education.
B. The disturbance in Criterion A sig. interferes with
achievement or activities of daily living that require reading.
C. If a sensory deficit is present, the reading difficulties are in
excess of those usually associated with it.

Coding Note: If a general medical (e.g., neurological) condition or
sensory deficit is present, code the condition of Axis III.
Using the DSM-IV-TR Model
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Look for chronic underachievement in reading:
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Interview teachers and parents at referral
Observe student’s reading continuum, past running
records, & results from informal reading inventories
Check cumulative file for comments & lower marks in
ELA, as well as failed progress in Reading Recovery
and/or Early Literacy Intervention programs
Look for family history of reading problems:
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Use background questionnaire &/or interview parents
Using the DSM-IV-TR Model
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Rule out competing explanations:
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Poor or inconsistent school attendance
Possible EAL status
History of home-schooling
Vision and hearing problems
CDC reports of global developmental delay &/or
below average intellectual level previously found
Little or no home support of literacy
Using The DSM-IV-TR Model
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Conduct individual standardized testing:
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Aptitude tests (e.g., WISC-IV)
Achievement tests (e.g., WIAT-II/GORT-IV or WIAT-III):
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Ensure you have tests of word reading, decoding or word
attack, comprehension, and reading fluency
A spelling test facilitates error analysis for sub-typing
Do ability-achievement discrepancy analysis (predicted
achievement > simple difference; sig. at p < .05; use a base
rate of 10% or lower for severe LD)
Include other processing tests that correlate with reading
achievement (e.g., PAT, CTOPP, PAL-II – phonological
awareness, orthographic awareness, rapid naming,
morphological awareness, TOC, SIT, NEPSY-II, etc.)
The Cross-Battery Model of LD
(Flanagan, Ortiz, Alfonso & Mascolo, 2006)
Four Level Approach:
 Level I-A, normative deficit in academic functioning
 Level I-B, exclusionary factors for academic deficit must be
ruled out
 Level II-A, normative deficits in cognitive abilities/processes
 Level II-B, exclusionary factors are ruled out for cognitive
deficits
 Level III, establish consistency between specific cognitive
deficits and specific areas of academic underachievement and
otherwise normal functioning in areas unrelated to academic
deficits
 Level IV, evidence of functional limitations in daily activities
related to the academic deficit
CHC Consistency Approach to
LD Diagnosis
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Gf: Inductive (I), and General Sequential Reasoning (RG) play a moderate role
in reading comprehension
Gc: Language Development (LD) and Lexical Knowledge (VL), and Listening
Ability (LS) play an important role and become increasingly important as
students age
Gsm: Memory span is important especially within the context of working
memory
Ga: Phonetic Coding or phonological processing is very important during
elementary school years
Glr: Naming facility or rapid automatic naming is very important during
elementary years
Gs: Processing speed is important during all school years particularly during
elementary
Moderate correlation with reading
Strong association with reading
Interpreting Results
Dyslexia Subtypes
The
universal
“Dyslexia
Signature”
based on
fMRI
research by
Dr. Sally
Shaywitz, et
al. 1998 &
2002
Dyslexic readers use compensatory
systems to read
Sally Shaywitz, Overcoming Dyslexia, 2003
Interpreting Results
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Phonological Dyslexia (~ 75%)
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(Decoding < reading comprehension) < AVERAGE
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Sight word recognition somewhat better than decoding
Reading fluency is typically slow (this may persist
even after remediation)
Primary deficits in phonological awareness (e.g.,
segmentation, deletion, blending, and so on of
syllables, phonemes, etc.)
Often weak in auditory working memory and factual
information
Has trouble spelling phonetically regular words
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Interpreting Results
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Surface or Orthographic Dyslexia (~ 15%)
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Primary deficit in orthographic processing
Decoding better than sight word recognition
Over-reliance on sound/symbol associations
Try to sound out every word (e.g., sign = /sig-en/)
Very slow and laborious reading speed
Interpreting Results
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Mixed dyslexia (~10 %)
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Involves reading/spelling features of both
phonological and orthographic dyslexia
Severely impaired in reading, and progress will be
very slow
Results in very bizarre error patterns & poor
syllabic representation:
e.g., Advice read as “Exvices”
– e.g., Material read as “Mitear”
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Rare Reading Disorder Subtypes
Hyperlexia - uncanny ability to decode words despite
significant cognitive deficiency. Comprehension very
poor. This may be found among those with Autism
Spectrum Disorder.
Deep Dyslexia - a reading comprehension disorder
characterized by impairments reading words with
abstract meanings; but reading more concrete,
easily imagined words are intact.
DeJerine Syndrome - dyslexia without dysgraphia.
Student has little difficulty writing, though cannot
read.
Two Reading Disorder Subtypes
Proposed by Dr. Byron Rourke
Phoneme-Grapheme Matching Disorder
Word Finding Disorder
Phoneme-Grapheme Matching
Disorder
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Key Deficit:
Phoneme-grapheme matching problems are paramount (most
often noticed in difficulties in translating graphemes to
phonemes)
– Grapheme-to-Phoneme Conversion: Convert a written
word (e.g., wharf) to its pronunciation or corresponding
sound sequence (e.g., W OW R F) during oral reading task
– Phoneme-Grapheme Conversion: Convert the sound
sequence /W OW R F/ to a written form /wharf/ during
spelling tasks
PGMD Prognosis
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Written spelling of sight words are average
Phonological awareness is normal
Poor auditory/verbal memory
Word decoding is poor, but not as severe as the
phonological core LD group
Matching printed to spoken words is poor
Written spelling of words not known “by sight” is poor
Writing letters and words to dictation is poor
Outcomes are much better than the phonologically
impaired LD group
Word-Finding Disorder
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Word-finding and verbal-expressive skill
deficits, within a context of a wide range of
intact skills and abilities (e.g., average
phonological awareness and phonemegrapheme matching skills)
NOTE: The only major deficit is difficulty in
accessing their normal store of verbal
associations.
WFD Prognosis
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Reading and spelling are very poor during
the early school years.
Near average or average performance in
these areas emerging towards grade 6-to-8.
Arithmetic and math reasoning seen as
strengths.
The PAL-II Model of Diagnosing Reading
Disabilities
Step 1
Has the child
had insufficient
opportunity to
learn English?
Does the child have
MR, ASD,
Language Disorder,
or social emotional
disorder
Does the child
have any
known genetic
disorders or
brain injury or
disease that
affects brain
function?
Step 2
Step 2
1. Obtain a reliable measure of Verbal Comprehension/ Crystallized IQ
- WISC-IV, WJ III, KABC-II, DAS-II, etc.
2. Assess the students:
- Sight-Word Knowledge (WIAT-II Word Reading; WJ III Letter-Word
Identification)
- Reading Comprehension
- Spelling
- Word Attack (WIAT-II Pseudoword Decoding; WJ III Word Attack)
- Reading Fluency (GORT-4; WJ III Reading Fluency)
• VIQ > 91? (and)
• Any reading or spelling test fall 15 points
below the mean?
Note: The size of the discrepancy may depend on the
amount of specialized instruction
Step 3
Assess the student’s phonological awareness, orthographic coding,
rapid automatic naming (naming facility), and executive abilities (inhibition &
switching)
Reliable Tests for Step 3
Phonological Awareness
•CTOPP
•PAT-II
•WJ III
•PAL-II
•NEPSY-II
Rapid Automatic Naming
•CTOPP
•PAL-II RAN subtests
•NEPSY-II Speeded Naming
Orthographic Coding
•PAL-II Receptive Coding
•PAL-II Expressive Coding
Executive Function
•Inhibition/Self-Monitoring
•D-KEFS Color-Word Interference
•NEPSY-II Inhibition
•NEPSY-II Auditory Attention
•Switching Attention or Stimuli/ SelfMonitoring
•NEPSY-II Letter/Number Naming
•PAL-II RAS
•NEPSY-II Inhibition
•D-KEFS Verbal Fluency: Category
Switching
Case Study: Estelle 11½ yrs.
Reason for Referral: Reading and spelling problems
Test Battery:
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WJ III (7 core tests+ 2 optional tests)
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NEPSY Word Generation
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WIAT-II Word Reading, Reading Comprehension, & Spelling
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WJ III ACH Reading Fluency
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Writing Sample
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PAL-II
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Phonological Coding (Syllables, Phonemes, & Rimes)
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Morphological Coding & Decoding
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RAN
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RAS
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Pseudoword Decoding
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Orthographic Coding
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Verbal Working Memory: Letters & Words
Note: 25 individual subtests
Estelle’s Assessment Results
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Cognitive Ability
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GIA/FSIQ= 101
Gc/VIQ= 96
Gf/Gv (PRI)= 109
Long Term Storage/Retrieval (Glr)= 110
Gsm=118 (Memory Span=109; Working Memory= 122)
Gs= 78 (Speed of Reasoning=96; Visual Perceptual Speed= 67)
READING/SPELLING ASSESSMENT:
Core Tests:
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Word Reading= 85
Reading Fluency= 86
Reading Comprehension= 92
Spelling= 79
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Spells phonetically
Errors on irregular words (e.g., kome for comb; juce for
juice), some digraphs & blends (e.g., ph, gh), vce rules
(kacke for cake), and r-controlled vowels.
Writing= 75
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Weak organization, grammar, idea generation, sequence
of ideas, content, vocabulary
Reading-Spelling Processes:
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Average Phonological Awareness (SS= 101)
Average Naming Facility
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Below Average Orthographic Awareness & Orthographic
Working Memory
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PAL-II Orthographic Processing Score= 70
NEPSY Word Generation (S & F words): below average
PAL-II Verbal Working Memory= 80
Below Average Word Attack Skills (phonological
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RAN= 90
PAL-II Pseudoword Decoding= 85
Executive Function (Switching Mental Sets)
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RAS= <85
Conclusions
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Surface Dyslexia
Disorder of Written Expression
Recommendations:
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Remedial Strategies:
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Barton Program (Level II)
Precision Reading (fluency & sight word knowledge)
Rosner Word Decoding Program (Decoding & Orthographic
Awareness)
Orthographic Awareness Activities (PAL-II)
Adaptations
Thank you
Any questions?