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3.3 Identifying Dyslexia

Decades of research and national test scores confirm that reading problems commonly occur and affect as many as one in five bright and motivated students who have average or above average intelligence. Adult literacy problems are also common, affecting one in four who are intelligent but have not been able to attain a functional literacy level. Research demonstrates that additional direct instruction provided appropriately, beginning in kindergarten through third grade, can help all but the most severely impaired students catch up to grade-level literacy skills and close the gap for most poor readers.  Assessment is the first step in identifying these students early to make sure they receive the effective instruction they need to succeed.

-International Dyslexia Association

In Section 3.2 - Early Screening of Reading Risk, the importance of early assessment of risk for reading failure was emphasized. However, the assessment of dyslexia is not limited to any specific age or time interval. School-aged students, or adults of any age, can be evaluated for dyslexia. This type of evaluation is frequently referred to as a diagnostic evaluation but is sometimes referred to as a multi-disciplinary evaluation, psycho-educational evaluation, educational evaluation or comprehensive education evaluation. Regardless of the name, the purpose of this type of evaluation is to determine whether the individual demonstrates the characteristics of dyslexia and to rule out other causes of the identified reading/writing concerns. Testing for dyslexia can verify the presence of a specific learning disability/dyslexia, can aid in determining the severity of the dyslexia, and can provide the needed documentation for eligibility for specially designed instruction (special education) and accommodations throughout an individual’s educational career from elementary school through college and postgraduate education.

A comprehensive diagnostic evaluation for dyslexia may be completed as part of the determination of eligibility for special education in a public school, or it may be administered in a hospital, clinic or private setting. Evaluations of this type may be completed by a team of professionals or by a single clinician depending on the setting. A primary-care physician or pediatrician may refer an individual to a dyslexia specialist, psychologist or neuropsychologist for assessment. A public school assessment team is likely to include an educational psychologist; a learning specialist or special education teacher; a speech-language pathologist; and a school social worker. Additional specialists such as an occupational therapist and/or a physical therapist might be involved in the evaluation process depending on the individual’s needs.Chapter 8: Dyslexia and Legislation details the legal requirements for special education eligibility as mandated by the Individuals with Disabilities Education Act (IDEA) or for accommodations as outlined in the Rehabilitation Act of 1974, Section 504.

The Process

In this section of the Colorado Dyslexia Handbook, the process and components of a comprehensive, diagnostic evaluation for dyslexia will be described.

Phase I: Collecting Background Information and Understanding the Referral Question/Concerns

The evaluation of reading disabilities and/or dyslexia involves the collection of information about family history, and the student’s birth, developmental, and medical history. This can be accomplished through an interview with parents or immediate family and, depending on age, the student. Questionnaires are often used to collect this information prior to the interview, so the clinician can focus on areas that have the most potential effect on the evaluation and the ultimate diagnosis during the interview. It is also important to review the student’s educational history, including school records, all prior assessment reports and intervention records. Sometimes, teachers and interventionists working with the students are asked to complete questionnaires as part of the data collection stage of the evaluation. Student work samples — for example, handwriting or spelling/writing samples — can also be reviewed when collecting data. During this stage of the evaluation process, it is important for the clinician or evaluation team to understand what concerns have led to the request for an evaluation.

Phase II:  One-On-One Assessment of Essential and Academic Skills and Abilities

Once the evaluation team or clinician has a solid understanding of the concerns that led to the evaluation and have compiled the background information, they will begin Phase II of the evaluation process. During this phase, the student will be administered a number of diagnostic measures during a one-on-one session or series of sessions. The assessment instruments utilized need to meet professional standards for reliability and validity, and are most commonly norm-referenced measures.

The evaluator should use assessment tools (tests) that are specifically designed to measure specific skills that align to the student’s age, grade and developmental needs. The following essential areas should be assessed during this phase of the diagnostic or educational/psycho-educational evaluation:

  • Expressive and Receptive Vocabulary — words the student uses when speaking and words the student understands when listening;
  • Listening Comprehension — what the student understands when listening to oral language at the sentence and passage level. Listening comprehension is often used as a gauge of the student’s potential for reading comprehension, when limited/inaccurate decoding does not impair comprehension of print;
  • Phonological/Phonemic Awareness — the student’s awareness of and access to the sounds structure of his/her oral language;
  • Rapid Automatized Naming — speed of naming common objects, letters, colors and/or digits;
  • Verbal Memory Skills — including phonological memory and the ability to recall sounds, syllables and words;
  • Alphabetic Principle and Phonics Skills — understanding that letter symbols represent specific sounds, and appreciating combinations and patterns of letters and their relationship to speech sound;
  • Decoding and Word Recognition — ability to use sound-symbol association to identify words and pseudo-words (nonsense words);
  • Oral Reading Fluency — the student’s ability to read single words and passages accurately, with appropriate phrasing and at a pace that supports comprehension;
  • Reading Comprehension — the ability to make meaning from print, including both oral and silent reading passages;
  • Spelling — the student’s ability to accurately encode words from dictation; and
  • Written Expression — the student’s ability to formulate sentences and passages using basic conventions of English (e.g., capitalization, punctuation, and grammar).

Most comprehensive diagnostic evaluations also include:

  • Math Calculation Skills — accuracy and automaticity of basic computational processes;
  • Math Fluency — the ability to quickly recall basic math facts;
  • Mathematical Problem-Solving — the ability for math reasoning and the completion of word problems;
  • Processing Speed — the student’s ability to complete simple tasks quickly; and
  • General Information — the student’s store of factual information often related to content areas of science, social studies and basic literature.

Some comprehensive diagnostic evaluations include:

  • Cognitive (Intelligence) Assessment — Cognitive testing is no longer required as part of the specific learning disabilities identification process. However, this type of assessment is often included to identify twice exceptional students (most commonly gifted students with dyslexia) or during the assessment of older students when their eligibility for accommodations at the college/postgraduate level or during high-stakes testing requires this type of assessment (e.g., college entrance exams, medical school entrance exams, the bar exam).


Phase III:  Scoring, Interpreting and Reporting Assessment Findings

Once all the testing is completed, the clinician or assessment team will score and analyze the assessment results. After this review and analysis, a written report is completed. The report should summarize important developmental and historical information, specifically highlight prior and pertinent assessment results, discuss current assessment data, and provide a clear interpretation and/or diagnosis of the assessment findings. A comprehensive report should draw specific recommendations from the assessment findings and highlight necessary accommodations. In some instances, the report will serve as a statement of eligibility for specially designed instruction (special education); in other instances, it may specifically serve to differentiate the diagnosis of dyslexia from other causes of poor reading or literacy. In all cases, assessment data should be reported as standard scores and percentiles, thus allowing for accurate comparison of growth over time and comparisons to others of the same age. The summary report should be shared with parents and professionals working with the child. It is also helpful for the child to receive an age-appropriate explanation of the evaluation outcomes.