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Curriculum Access for Students with Low-Incidence Disabilities: The Promise of UDL

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What are low-incidence disabilities?


Alternative Systems for Classification

Students with disabilities can be classified in many ways. IDEA '97 continues to recognize disabilities in the form of more or less discrete diagnostic categories, such as mental retardation, specific learning disabilities, or emotional disturbance. Other approaches to classification include categorizing disabled individuals by degree of severity of their needs, or by how atypical an individual may be when compared to a norm. Still other approaches may emphasize the level of intensity of supports necessary for an individual to function optimally in home, school, community, and work settings.

Each of these approaches has advantages and disadvantages. The categorical approach taken by IDEA may emphasize learner characteristics for each disability, but, in so doing, it could also foster a self-fulfilling prophecy in which all members of a group sharing a categorical label, in a sense, become that label. A severity approach may emphasize developmental milestones at the expense of ignoring strengths in functional skills. An intensity approach may meaningfully focus on levels of needed support, but, at the same time, limit opportunities for an individual to move to a less restrictive setting. None of these systems of classifying individuals with disabilities are either entirely satisfactory or entirely lacking in merit. For educators, it is important to be aware that several systems of categorizing students with disabilities exist simultaneously, because eligibility criteria, placement alternatives, intervention strategies, and teaching credentials may all vary substantially from school to school, depending on which system of classification is currently being employed.


A Focus on Incidence

When the issue at hand for students with disabilities centers on the provision of services in local schools, the availability of qualified personnel and the technical sophistication of necessary resources must be carefully considered. In order to provide students with disabilities with a free and appropriate public education, it is useful to classify learners in terms of incidence, or how many students with any particular disability or combination of disabilities reside in a community. Under such a system, students with the most commonly-seen disabilities may be more appropriately served by local public schools while students with relatively rare disabilities may not find adequate resources or highly qualified personnel.

High-incidence disabilities include—

  • communication disorders (speech and language impairments)
  • specific learning disabilities (including attention deficit hyperactivity disorder [ADHD])
  • mild/moderate mental retardation
  • emotional or behavioral disorders

Low-incidence disabilities include—

  • blindness
  • low vision
  • deafness
  • hard-of-hearing
  • deaf-blindness
  • significant developmental delay
  • complex health issues
  • serious physical impairment
  • multiple disability
  • autism


None of the disabilities listed under low-incidence disabilities generally exceed 1% of the school-aged population at any given time. The relative rarity of students with these disabilities in public schools often poses significant challenges for local schools struggling to meet their needs. Since they encounter these students so infrequently, most local schools have little if any knowledge of how to best educate these students, of what technologies are available to assist them, and of how to obtain needed and appropriate support services from outside agencies. All students with low-incidence disabilities thus experience a commonality: they are difficult to serve in current local public school programs.


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Last Updated: 11/05/2010

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