Dyslexia Glossary

As with most specialized areas, dyslexia comes with its own vocabulary. And, to make matters more challenging, the professionals in the varying fields who diagnose and treat language disability and dyslexia may even use different words to refer to the same behavior.

For example, many public schools do not use the term dyslexia and instead refer to it as a "specific learning disability" (which it is) in reading with difficulties in written word decoding and /or reading comprehension.

We have identified a list of common terminology and phrases often used by education and medical professionals (e.g., psychologists, physicians, speech-language pathologists) in diagnostic reports, individual educational plans (IEPs), and therapy. Don’t feel overwhelmed if you don’t understand all of the terms or acronyms. These words and concepts were new to us as professionals once upon a time, too! When in doubt, ask for clarification.

Age equivalent (AE): Age equivalency refers to the median raw score for a given age level. Age (and grade) equivalents have limited reliability and validity, therefore, standard scores better represent one's ability.

Americans with Disabilities Act of 2008 (ADA): The ADA is the civil rights act supporting the rights of individuals with disabilities in relation to public building accessibility, employment, housing, etc. ADA was signed into law in 1990 but was re-authorized as the American with Disabilities Act Amendments Act (ADAAA) in 2008.

Basic rights covered by Americans with Disabilities Act Amendments Act (ADAAA)

  • Expands the definition of disability under the orignial Americans with Disabilities Act, preventing discrimination in employment and in public and private settings
  • Protects children and adults with disabilities
  • Applies to all public and most private schools and colleges, testing agencies, licensing authorities, and state and local governments


Apraxia: Children with apraxia typically have trouble saying sounds, syllables, and words. Contrary to popular belief, it is not due to muscular weakness but instead to the brain’s planning of how to move the body parts needed for speech. The child knows what he wants to say, but the brain does not give the necessary instructions. (American Speech-Language-Hearing Association)

Articulation Disorder: Children with articulation problems have difficulty in the production of speech. This is often due to problems in the integration of movement in the lips, tongue, velum, or pharynx.

Assistive Technology (AT): AT is software, hardware, devices or services that improve the functional skills and abilities of students with disabilities. An Assistive Technology Evaluation may be requested by staff or parents as part of the Individualized Education Plan (IEP) planning process. Identified services or devices are specified in the Supplemental Aids/Services/Personnel Support section of the IEP (Individual Education Plan).

Attention Deficit Hyperactivity Disorder (ADHD): Children with ADHD usually present with many symptoms, including the inability to attend (such as listening to and following directions), impulsivity, distractibility, clumsiness, and hyperactivity. ADHD is thought to be caused by a slight abnormality in the functioning of the brain. In Attention Deficit Disorder (ADD), hyperactivity is not a factor. Often children are diagnosed prior to the age of four.

Baseline: The level at which an individual performs before training or intervention has started. It is important to know this information so that changes can be measured and progress can be quantified over time.

Chronological age (CA): An individual actual age; usually stated in exact years and months (e.g., 8.11 means a child is eight years and eleven months old).

Decoding: The ability to use letter-sound relationships to translate a written word into a spoken word. It is commonly described as the ability to "sound out" a new word.

Developmental Language Disorder-Mixed: Children with developmental speech and language disorders have difficulty producing speech sounds, using spoken language to communicate, and/or understanding what other people are saying. This type of language disorder is often more indicative of a broader learning disability or even autism, which will become more evident as children reach elementary-school age. Children can be specifically classified as having a Developmental Articulation Disorder, Expressive, and/or Receptive Language Disorder.

Dyslexia: Children with language-based learning disabilities experience difficulties with age appropriate reading, spelling, and/or writing. Dyslexia is the most common language-based learning disability. We now know that there is a relationship between spoken language and written language, so children with dyslexia have trouble transferring expressive and receptive language into written language. Children with dyslexia do not have inferior intelligence; they merely have a disorder related to brain functioning. (American Speech-Language-Hearing Association)

Equivalent score: An equivalent score indicates the individual’s performance on a test in comparison with other populations who have taken the same test. There are age-equivalent scores and grade-equivalent scores.

Extended School Year (ESY) Services: ESY Services are services that are often provided beyond the mandated 180 school days (from September to June). There is a process to go through to see if a student qualifies for ESY services. This item is included on the IEP form and requires a discussion and team-based decision.

Free Appropriate Public Education (FAPE): FAPE is a free and individualized educational program in the least restricted environment entitled to students with disabilities under the Individuals with Disabilities Education Act (IDEA).

Grade equivalent (GE): Grade equivalency refers to the median raw score for a particular grade level. Grade (and age) equivalents have limited reliability and validity, therefore, standard scores better represent one's ability.

Hyperlexia: Children with hyperlexic tendencies have a precocious ability to decode single words and numbers very early in their development. Often these children are reading (decoding) or writing prior to speaking, but because of their oral language delay, their comprehension is poor. Exceptional decoding skills can be seen in children diagnosed with Autism Spectrum Disorder (ASD) at very young ages.

Independent Education Evaluation (IEE): IEE Evaluations are requested by districts and/or parents when there is disagreement about a student’s diagnosis.

Individualized Education Program (IEP): An IEP is the detailed program plan that is developed for each individual student with special needs.

Individualized Education Program Team (IEPT) The IEPT is a group of individuals involved in the planning and implementation of a student’s IEP including a principal, teaching consultant (TC), general education teacher, psychologist, social worker, speech-language pathologist, occupational therapist, and parent/guardian.

Individualized Family Service Plan (IFSP): An IFSP is similar to an IEP but designed for children under the age of three.

Individuals with Disabilities Education Act of 2004 (IDEA, Federal Public Law 105-17): This is the law that sets national standards for educating students with disabilities. The original law was called the Education of all Handicapped Children Act of 1975 (Public Law 94-142). It was re-authorized as the Individuals with Disabilities Education Act in 1997 and was revised again in 2004.

Intermediate School District (ISD): Set up in 1962, there are 57 regional educational service agencies (i.e., ISDs) in the State of Michigan that help local school districts educate students (especially those with disabilities). ISDs coordinate programs and services that are often highly specialized and too costly for local districts to support.

Least Restricted Environment (LRE): The LRE is the IDEA requirement that each student with a disability be educated, as much as possible, with nondisabled peers in general education classes and activities.

Letter-sound correspondence: The relationship between a letter or letter combination and a single sound. For example, the letter “j” and the letter combination “dge” both make the sound heard in the beginning of the word “jump.” An understanding of letter-sound correspondence (also called grapheme-phoneme correspondence) is essential for decoding a new word.

Mental age (MA): The level or age equivalent at which a child realistically functions or performs. (MA is routinely used in Intelligence Quotient (IQ) testing, where test results indicate the actual developmental age of a child’s cognition and behavior.) Some clinicians use the term Developmental Age in place of MA. For example, if a child is 4.6 years old and is assigned an MA of 3.6, then the report is indicating that he or she is one year behind.

Metalinguistics: A learned understanding of the function and use of language structures and rules.

MI-Access: This is Michigan’s alternative assessments to the MEAP that are specifically geared toward students with disabilities. One of four assessments is selected based on the student’s anticipated level of independence in adulthood.

Multidisciplinary Evaluation Team (MET): The MET is a comprehensive evaluation process that is scheduled every 3 years for special education certification. (It is currently under review at the federal level and therefore subject to changes in Michigan)

No Child Left Behind Act of 2001 (NCLB): The NCLB is the Federal law that requires school accountability for student achievement, including the hiring and placement of highly qualified teachers in all core curriculum subjects. Every school must meet Adequate Yearly Progress (AYP) standards, which are monitored by the state and reported to parents on an annual basis.

Nonverbal Learning Disorders: These are neurologically based syndromes describing specific assets and deficits. The assets include early speech and language development, strong rote memory skills, attention to detail, and early reading and spelling skills. The deficits include motoric problems with coordination, balance, and graphomotor skills; visual spatial organizational problems; social deficits in their ability to comprehend nonverbal communication/gestures and deficits in social judgment; and sensory difficulties in any of the sensory modes–visual, auditory, tactile, taste, and olfactory (i.e., smell). Executive functioning skills are usually weak (planning, organizing, sequencing, initiating, emotional regulation, and impulse control).

Norm-referenced test: This refers to an assessment that has been used on a population of individuals that has similar characteristics as the individual being tested. Normed tests very often refer to a broad population of individuals who have been tested with the same instrument, according to age and/or grade. But there are other considerations as well; for instance, a test normed on a population of Spanish-speaking children may not accurately identify a language delay in an English-speaking child.

Percentile rank: A percentile rank reflects the percentage of other individuals who have taken the same test and received the same score or a lower score than a person’s score. Percentiles are described on a scale of 1 to 99 and are useful for illustrating one’s relative standing in a population. For example, if a child is in the 80th percentile, he or she has scored the same as or better than 80% of test takers.

Pervasive Developmental Disorder (PDD): PDD is a broad category of disorders, characterized by varying degrees of impairments in language, communication, and social interaction. Often children present with repetitive and stereotypical interests and behaviors as well. PDDs are commonly referred to as Autism Spectrum Disorders (ASD). There are five subcategories within the PDD classification: Autism, Asperger’s Syndrome (AS), Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS), Rett’s Syndrome, and Childhood Disintegrative Disorder (CDD). ASDs are usually diagnosed by the age of three and are four to five times more common in boys than girls. For a comprehensive description of ASD, refer to the Diagnostic Statistical Manual of Mental Disorders-IV (DSM-IV), published by the American Psychiatric Association.

Phonics: An understanding of the relationship between written letters and corresponding sounds (letter-sound correspondence). In reading instruction, a phonics approach teaches readers to decode words using letter-sound correspondence and to recognize exceptions from these rules.

Phonological awareness: The awareness of and access to the sound structure of speech. It includes the ability to attend to and manipulate the sounds in words. An example includes knowing that the word "sit" includes three sounds (s, i, t) and that changing the first sound to /b/ makes the word "bit."

Phonological memory: Temporary storage of phonological information in short-term memory.

Phonological processing: The ability to use phonological information to process written and oral language. It is composed of an individual’s phonological awareness, phonological memory, and rapid naming skills. Examples include the ability to say words, recall lists of information, name rhyming words, and separate words into individual phonemes.

Phonology: The set of rules that determines how sounds are combined to make words within a given language.

Positive Behavioral Support (PBS): PBS is a process and philosophy that helps students with behavioral problems succeed in school using functional analysis and positive reinforcements to affect behavioral change.

Pragmatics: Rules governing the use of social use language. These include using language for different purposes (requesting, greeting, describing), changing language based upon the listener (providing more or less information based on the listener’s knowledge, speaking differently to a child vs. an adult), and following rules within conversations (continuing a topic, using nonverbal cues).

Present Level of Academic Achievement and Functional Performance (PLAAFP): This is a description of the student’s present level of functioning and how the individual’s disability impacts his/her progress in the general education curriculum (achievement) and setting (behavior/function).

Procedural Safeguards: Available to parents of students with disabilities, this document outlines a student’s (and his/her parents’) rights with respect to the state regulations that govern special education. This document should be provided to parents at every annual IEP meeting

Prognosis: An estimate of the course and outcome of a disease/disorder, which represents a performance profile at the time of diagnosis but is rooted over time. For example, a speech-language pathologist may state in an initial evaluation that "the prognosis for attaining these objectives is fair."

Rapid automatic naming: A skill requiring fast and effective retrieval from information about phonology from long-term memory and being able to use the information effectively. Examples include quickly naming a list of objects, letters, or numbers.

Raw score: A raw score in and of itself is relatively unimportant. This usually represents the total number of correct responses. Raw scores can be converted to percentile ranks, standard scores, grade equivalents, and age equivalents.

Reading comprehension: An understanding of the information read within a text.

Reading fluency: A measure of the accuracy and speed (or rate) of reading. Decreased reading fluency typically reduces overall comprehension due to the additional effort and time required to read the text.

Response to Intervention (RtI): RtI is a scientific, research-based approach developed to provide a collaborative problem solving framework to address the learning needs of students who are not achieving commensurate with their peers, using grade-specific benchmarks. Student outcome data is the determining factor for either increasing or changing the research-based instruction or intervention being used to help the student achieve academically. RtI is a multi-step process, with systematic monitoring and is routinely implemented prior to assessing a student for special education services.

Scaled score: A scaled score is a conversion of a one’s raw score that allows for comparison between other students and also for the same student over a period of time.

Section 504: This section of the Rehabilitation Act of 1973 protects the rights of individuals with disabilities. It is a civil rights act that applies to individuals with less severe impairments. Often, Section 504 plans support curricular accommodations or classroom modifications for students with attention issues, allergies, and/or physical limitations.

Semantics: The meanings of words, phrases, or sentences within a given language.

Short-term memory: Brief, verbatim storage of auditory information. It is often called "working memory," because it is used for remembering a small amount of information for immediate use, such as remembering a phone number long enough to dial. Short-term memory is an important component in reading, as it allows the reader to remember a string of individual sounds and then blend then the sounds together when decoding an unfamiliar word.

Sight word: Words that are memorized or easily recognized without being decoded in a sound-by-sound manner. These tend to be high-frequency words. During reading instruction, words that do not follow basic rules of phonology ("exception words") are usually explicitly taught as sight words. Examples include "there" and "again." These can be particularly difficult for the young dyslexic.

Specific learning disability (SLD): SLD means a "disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, which may manifest itself in an imperfect ability to listen, think, speak, read, write, spell, or to do mathematical calculations. The term includes such conditions as perceptual handicaps, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. The term does not include children who have learning problems which are primarily the result of visual, hearing, or motor handicaps, of mental retardation, or emotional disturbance, or of environmental, cultural, or economic disadvantage." (National Advisory Committee on Handicapped Children, 1967, that is included in PL 94-142).

Standardized: This term is often used interchangeably with norm-referenced. It involves a process of assessing a sample population in order to establish general evaluative criteria. A standardized test evaluates a child using consistent criteria, administration, and scoring.

Standard deviation (SD): This is a value which the test developer establishes during test construction. It represents the degree to which a given test score is expected to differ from the mean or average score. Fifteen points above or below the mean score of 100 on an IQ test is considered one standard deviation, so a score of 85 indicates that the child is considered one standard deviation below the mean. One standard deviation below is often considered a cut-off for a typical performance. Therefore a child who receives a score greater than 85 is within normal range (and over 115 gets into the above average performance range) and a performance score of below 85 is considered below average and evidence of atypical or delayed development.

Standard score: A standard score is developed for most tests and represents the score that is expected for an individual of a specific age. For many tests, the expected standard score is 100, and plus or minus 15 (the SDs) establishes the range of “typical” performance scores. Therefore if a child receives a standard score of 105, this will be interpreted as average performance on the test, because that score is within 15 points above 100.

Syntax: Rules regarding combining words to make grammatically correct sentences. For example, the sentence "I went to work this morning" is correct, while "Went to work I did this morning" does not follow English rules of syntax.