Dyslexia can affect reading accuracy, reading fluency, spelling, written expression, comprehension, academic performance, workplace efficiency, and confidence. At Rogerian Psychology Centre, our Dyslexia Assessment service is designed for both children and adults who may be experiencing persistent difficulties with reading, spelling, writing, phonological processing, or learning despite adequate effort, instruction, and intelligence.
Our assessment provides a structured understanding of the individual’s learning profile by examining cognitive ability, academic attainment, phonological processing, and literacy-related skills. The goal is not only to determine whether dyslexia is present, but also to identify the person’s strengths, weaknesses, and practical support needs.
Who Is This Assessment Suitable For?
This assessment is suitable for children, adolescents, and adults who experience ongoing difficulties with reading, spelling, writing, or learning. It may be appropriate for students who read slowly, struggle with spelling, avoid written tasks, have difficulty sounding out words, confuse similar-looking words, or perform below expectation despite normal classroom exposure.
For adults, dyslexia assessment may be useful when there are longstanding difficulties with reading fluency, written communication, workplace documentation, spelling, processing written information, or professional examinations. Some adults seek assessment because their difficulties were missed during childhood, while others require formal documentation for workplace or educational accommodations.
Common Reasons for Dyslexia Assessment
People typically seek a dyslexia assessment when there are concerns such as slow or inaccurate reading, poor spelling, weak phonics skills, difficulty decoding unfamiliar words, problems with written expression, inconsistent academic performance, avoidance of reading-heavy tasks, or a family history of dyslexia or learning difficulties.
The assessment may also be needed for school support planning, examination accommodations, university access arrangements, workplace adjustments, or clarification of whether the difficulties are due to dyslexia, attention problems, language weaknesses, anxiety, or broader learning issues.
Assessment Tools Used
Our dyslexia assessment uses internationally recognised assessment batteries to provide a comprehensive learning profile.
For cognitive assessment, children are typically assessed using the WISC, while adults are assessed using the WAIS. These tools examine areas such as verbal reasoning, visual-spatial reasoning, working memory, processing speed, and broader intellectual functioning. This helps determine whether literacy difficulties are occurring in the context of otherwise appropriate cognitive ability.
The WIAT is used to assess academic achievement, including reading, spelling, written language, and related literacy skills. This helps identify the individual’s actual academic performance and whether there are significant weaknesses in literacy-based areas.
The CTOPP-2 assesses phonological processing, including phonological awareness, phonological memory, and rapid naming. These skills are strongly linked to dyslexia and are important for understanding the underlying reasons behind reading and spelling difficulties.
Assessment Process
The assessment is conducted over two sessions, with a total testing time of approximately six hours. The two-session format allows the psychologist to assess the individual thoroughly while reducing fatigue and maintaining test accuracy.
The process typically includes an initial clinical and educational history review, followed by standardised testing using the WAIS or WISC, WIAT, and CTOPP-2. The psychologist will examine the individual’s cognitive profile, literacy performance, phonological processing skills, and functional difficulties in school, work, or daily life.
After the assessment is completed, the results are analysed and compiled into a formal psychological report. The report includes test scores, clinical interpretation, diagnostic impressions where appropriate, and practical recommendations for intervention, learning support, school accommodations, examination access arrangements, or workplace adjustments.
Benefits of Dyslexia Assessment
A dyslexia assessment helps clarify why a person may be struggling with reading, spelling, or writing. It can provide validation, reduce self-blame, and offer a clear explanation for difficulties that may have persisted for years.
For children, early identification can guide targeted intervention, school support, and learning strategies before academic frustration becomes more severe. For adolescents and university students, assessment can support applications for examination accommodations or learning support services.
For adults, assessment can help explain longstanding literacy challenges and support reasonable workplace or educational adjustments. It can also help distinguish dyslexia from other possible factors such as ADHD, anxiety, low confidence, limited instruction, or general learning difficulties.
Cost
The full Dyslexia Assessment costs $2,800, inclusive of the assessment sessions and a formal psychological report.
Scientific Rationale for Test Selection
The dyslexia assessment battery employed at Rogerian Psychology Centre is grounded in contemporary evidence-based practice and aligns with internationally recognised recommendations for the assessment of Specific Learning Disorder with impairment in reading (dyslexia). Dyslexia is understood as a neurodevelopmental condition characterised by persistent difficulties in word recognition, decoding, spelling, and phonological processing despite adequate educational opportunities and intellectual capacity.
A comprehensive evaluation therefore requires assessment across three domains:
- Cognitive Ability (WAIS or WISC)
- Academic Achievement (WIAT)
- Phonological Processing (CTOPP-2)
WAIS / WISC: Evaluation of Cognitive Ability
Assessment of intellectual functioning is an essential component of dyslexia evaluation. Instruments such as the WAIS and WISC provide detailed information regarding verbal reasoning, visual-spatial abilities, working memory, and processing speed.
Although the historical discrepancy model between intelligence and achievement is no longer considered sufficient for diagnosis on its own, cognitive assessment remains clinically important for understanding an individual’s learning profile, identifying relative strengths and weaknesses, and differentiating dyslexia from broader intellectual difficulties or global developmental concerns.
Research has demonstrated that individuals with dyslexia often display average to above-average intellectual abilities alongside specific deficits in literacy acquisition, making cognitive assessment an important interpretive component of a comprehensive evaluation.
WIAT: Measurement of Academic Achievement
The Wechsler Individual Achievement Test (WIAT) is widely regarded as one of the most comprehensive measures of academic attainment and is frequently utilised in psychoeducational and learning disorder assessments.
The WIAT evaluates:
- Reading accuracy
- Reading fluency
- Pseudoword decoding
- Reading comprehension
- Spelling
- Written expression
- Oral language abilities
Assessment of academic achievement enables clinicians to determine the severity and pattern of literacy difficulties and identify whether reading and writing performance falls significantly below age and educational expectations.
Pearson Clinical notes that WIAT dyslexia-related indices are specifically designed to support the identification of individuals at risk for reading disorders. (Pearson Clinical)
CTOPP-2: Assessment of Phonological Processing
Deficits in phonological processing remain one of the most consistently replicated findings in dyslexia research. The Comprehensive Test of Phonological Processing – Second Edition (CTOPP-2) evaluates core reading-related processes including:
- Phonological Awareness
- Phonological Memory
- Rapid Automatized Naming
- Rapid Symbolic Naming
- Nonword Repetition
These processes are strongly associated with literacy development and constitute a key component of modern dyslexia assessment frameworks.
The CTOPP-2 has demonstrated strong psychometric properties, with internal consistency coefficients generally exceeding .80 and composite reliabilities above .85. (PAR Inc.)
Studies have consistently shown that phonological processing difficulties are highly associated with reading impairments and developmental dyslexia. (Wiley Online Library)
Contemporary evidence further suggests that reading ability reflects the interaction of phonological processing, working memory, processing speed, and attentional mechanisms, reinforcing the importance of a multidimensional assessment approach. (PMC)
Suggested References
References
Catts, H. W., Hogan, T. P., & Adolf, S. M. (2005). Developmental changes in reading and reading disabilities. In H. W. Catts & A. Kamhi (Eds.), The connections between language and reading disabilities (pp. 25–40). Lawrence Erlbaum Associates.
Dickens, R. H. (2015). Test review: Comprehensive Test of Phonological Processing–Second Edition (CTOPP-2). Journal of Psychoeducational Assessment, 33(4), 391–395.
Kibby, M. Y., Lee, S. E., & Dyer, S. M. (2014). Reading performance is predicted by more than phonological processing. Frontiers in Psychology, 5, 960. https://doi.org/10.3389/fpsyg.2014.00960 (PMC)
Mundy, I. R., Carroll, J. M., & Cunningham, A. J. (2020). Exploring the phonological profiles of children with reading difficulties. Dyslexia, 26(3), 265–283. (Wiley Online Library)
Shaywitz, S. E. (2003). Overcoming Dyslexia: A New and Complete Science-Based Program for Reading Problems at Any Level. Alfred A. Knopf.
Wagner, R. K., Torgesen, J. K., Rashotte, C. A., & Pearson, N. A. (2013). Comprehensive Test of Phonological Processing–Second Edition (CTOPP-2). Austin, TX: Pro-Ed. (Pearson Assessments)
Wechsler, D. (2014). Wechsler Intelligence Scale for Children – Fifth Edition (WISC-V). Bloomington, MN: Pearson.
Wechsler, D. (2020). Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV). Bloomington, MN: Pearson.
Wechsler, D. (2020). Wechsler Individual Achievement Test – Fourth Edition (WIAT-IV). Bloomington, MN: Pearson.
These references provide a strong evidence base to justify the inclusion of the WAIS/WISC, WIAT, and CTOPP-2 within a comprehensive dyslexia assessment protocol for both children and adults.
Dyslexia Assessment Options with Rogerian Psychology Centre
At Rogerian Psychology Centre, we offer two evidence-based dyslexia assessment pathways to meet differing clinical, educational, and accommodation needs.
Option 1: Comprehensive Dyslexia Assessment
Assessment Batteries
- WAIS-IV (Adults) or WISC-V (Children)
- WIAT-4
- CTOPP-2
Duration: Approximately 6 hours across 2 sessions
Cost: $2,800 (inclusive of report)
This is our most comprehensive dyslexia evaluation and is recommended for individuals requiring an in-depth understanding of their literacy profile. In addition to cognitive ability and academic achievement, the CTOPP-2 provides detailed assessment of phonological awareness, phonological memory, and rapid naming skills, which are core processes commonly implicated in dyslexia.
This option is particularly suitable for complex presentations, long-standing learning difficulties, diagnostic clarification, intervention planning, or cases where a highly detailed assessment is required.
Option 2: Dyslexia Screening and Educational Assessment
Assessment Batteries
- WAIS-IV (Adults) or WISC-V (Children)
- WIAT-4
Duration: Approximately 4 hours across 2 sessions
Cost: $1900 (inclusive of report)
The WIAT-4 is the latest edition of the Wechsler Individual Achievement Test and includes measures relevant to reading-related processes, including aspects of phonological processing, decoding, reading fluency, spelling, and written language skills. As such, many individuals can obtain a robust understanding of their learning profile through the combination of cognitive assessment and WIAT-4 alone.
This assessment pathway is suitable for individuals seeking clarification of reading and spelling difficulties, educational support recommendations, or school-based accommodations where an extended phonological assessment may not be clinically necessary.
Comparison of Dyslexia Assessment Options
| Feature | Comprehensive Assessment | Educational Assessment |
|---|---|---|
| Cognitive Assessment | WAIS-IV / WISC-V | WAIS-IV / WISC-V |
| Academic Achievement | WIAT-4 | WIAT-4 |
| Dedicated Phonological Assessment | CTOPP-2 Included | Embedded WIAT-4 Measures Only |
| Reading Accuracy | ✓ | ✓ |
| Reading Fluency | ✓ | ✓ |
| Spelling Assessment | ✓ | ✓ |
| Phonological Awareness | Extensive | Basic–Moderate |
| Rapid Naming Assessment | ✓ | Limited |
| Phonological Memory | ✓ | Limited |
| Diagnostic Detail | Very High | Moderate–High |
| Intervention Planning | Extensive | Good |
| Accommodation Documentation | Excellent | Good |
| Sessions | 2 Sessions | 2 Sessions |
| Total Duration | ~6 Hours | ~4 Hours |
| Report Included | Yes | Yes |
| Cost | $2,800 | $1,900 |
Clinical Considerations
While the WIAT-4 incorporates several literacy and phonological indicators, the CTOPP-2 remains the gold standard for detailed evaluation of phonological processing abilities. Consequently, the comprehensive option may be preferred when diagnostic certainty is required, when difficulties appear severe or longstanding, or when highly detailed intervention planning is needed. Conversely, the WAIS/WISC plus WIAT-4 pathway offers a streamlined and efficient assessment for many educational and practical purposes.