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

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What are the needs of students with low-incidence disabilities?


Special Education is Not a Place

With the enactment of IDEA '97, special education is no longer considered a place but rather a network of services and supports designed to enable students to derive full benefit from a public school education (Heumann & Hehir, 1997). As stated earlier, this does not mean that students with disabilities cannot be appropriately served in specialized settings. Rather, the intent of the law is to emphasize that "placement" or location of services is the last decision an IEP team makes during a team assessment and planning process. In earlier times, a disability-specific label itself would dictate placement, and that placement would define the treatment or nature of interventions for students. Today's approaches use comprehensive and holistic assessments to reveal the extent of need in suspected areas of risk associated with a student's disability. Their team then determines the setting in which needed services can best be provided, selecting from a continuum or array of placement options ranging from full inclusion in a general education classroom to residency in a hospital setting (Drasgow, Yell, & Robinson, 2001). An IEP team always starts with the presumption that a student will be placed in the same setting in which he or she would be educated if disability were not an issue, namely, a regular public school classroom (Turnbull & Turnbull, 1998). Thus, in order to place a student in a less inclusive setting, this starting presumption must be rebutted by assessment data before such a placement outside a general education setting can be made.


Categories and Characteristics

IDEA designates categories of disability with which specific learner characteristics have been associated in the special education knowledge base (Hallihan & Kaufman, 2002; Hardman, et al., 2002; Heward, 2003; Turnbull, et al., 2002). These characteristics are correlates of particular disabilities and not necessarily connected with a particular disability—that is to say, they are characteristics that are commonly found in students with these particular disabilities, but for which there are often exceptions, such as cases where a student has a particular disability but not one or more of its expected associated characteristics or behaviors. "Learned helplessness," for example, is associated with specific learning disabilities, but not all students with learning disabilities have acquired this psychological adaptation. Rather, they are at risk for acquiring learned helplessness. While there are often litanies of learner characteristics described as unique or disability-specific, the extent to which these areas of risk are observed in an individual student can vary widely. Careful assessment and observation of an individual student and his or her needs must be undertaken to document actual need for initial intervention and not merely expected need. Such an assessment establishes a baseline of educational need(s) against which progress can be measured.

Students with disabilities often become "handicapped"—unnecessarily or unfairly restricted—not by their disabilities in and of themselves, but by the environment in which they live, learn, and relate. Consequently, extent of need cannot adequately be assessed without consideration of broader contexts in which an individual lives. This context includes family, community, and the local public school which would be a student's default placement location. Thus, a team's determination of the least restrictive and most appropriate environment for a student must take all these factors into consideration when judging the capacity or preparedness of home, community, and local school to support and nurture a student in areas of assessed need and in assuring a student access to the general curriculum. It is imperative that any set of disability-specific needs not serve to stereotype a student, to lower expectations for a student, or to contribute to negative self-fulfilling prophecies for a student. So-called unique or disability-specific needs should be taken only as possible areas of risk for IEP teams to investigate, not inevitable features automatically conjoined to a specific disability in question.


Addressing Intense and Complex Needs

Identified needs of students with low-incidence disabilities are frequently complex and multiple (Browder, 2001). Addressing severe and complex needs of students is challenging for family, school, and broader community. Since the ultimate goal of education is community inclusion and high quality of life, an appropriate education must contain opportunities for each individual to achieve independence, enjoy community participation, and increase productive and rewarding work to the maximum extent possible. Most children identified by IDEA categories as having low-incidence disabilities possess sensory, motor, or neurological deficits, and, consequently, they are typically identified and managed early in their lives through a medical model. Families of infants and toddlers with established risks receive early intervention services, most generally under the auspices of state departments of public health. Such services prepare a family and their local community to understand and cope with the impact of a child's disability on their lives. Such services also prepare a family to actively participate in the planning and decision-making processes that accompany transitional events throughout the child's life. Thus, early intervention and early childhood education can be effective in preventing or minimizing many long-term and predictable consequences of disability.

Because of the possibility of mitigating many of the consequences of disability early on in a child's life, possibly to the point where a disability essentially vanishes, IDEA encourages states to withhold disability categorization until age nine. The more generic term developmental delay is used instead, to avoid the stereotyping and lowered expectations that follow disability-specific labeling. However, states still have the option of using, for example, the terms "blind" or "deaf" if preferred. According to IDEA '97),decisions made about a child with a disability must be informed by "persons knowledgeable about the disability" or by "qualified professionals." States must "qualify" professionals through certification or licensure. Thus, for blind students to receive specially-designed instruction in Braille literacy, deaf students in ASL, and motor-impaired students in augmentative communication, states must ensure that an adequate supply of appropriately prepared professionals is available to support such students in educational programs. The need for the specialized knowledge and skills possessed by these professionals is often cited as a basis for retaining IDEA's system of categorical labeling, as well as states' systems for categorical teacher certification (Hallihan & Kaufman, 2002).


Clusters of Low-Incidence Disabilities

Hereafter, low-incidence disabilities are defined and described under the following headings:

  • Blind/Low Vision
  • Deaf/Hard-of-Hearing
  • Deaf-Blind
  • Significant Developmental Delay
  • Significant Physical and Multiple Disabilities
  • Autistic Spectrum

Note that some of these headings do not match with IDEA's current categories, being more general. Where appropriate, legal categorical definitions are quoted from IDEA '97 in the text so that readers will note congruence with federal law.

Blind/Low Vision

According to IDEA '97,
Visual impairment including blindness means an impairment in vision that, even with correction, adversely affects a child's educational performance. The term includes both partial sight and blindness.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Historically, students with visual impairment have been referred to as blind, visually handicapped, visually disabled, visually impaired, partially sighted, partially blind, visually limited, or sight impaired. To understand the needs of students with visual impairments, the following factors must be taken into account: age at onset of visual impairment, degree of impairment, site of impairment, prognosis for improvement or degeneration in condition, day-to-day stability of condition, individual tolerance for visual fatigue, and the extent and complexity of any co-existing additional impairments.

Blind children are particularly challenged in understanding and moving about in physical space (Blasch, Wiener, & Welch, 1997). Without opportunity to directly observe space during locomotion, blind children have difficulty mentally representing and manipulating spatial concepts. They are also challenged in obtaining, manipulating, and producing many types of information, such as text, graphics, facial expressions, and gestural cues (Swensen, 1999). Achieving self-esteem is also difficult for blind children since self-awareness in the social context of school is often affected by such factors as social isolation, low expectations, and over-protection (Tuttle & Tuttle, 1996).

Classroom instruction typically exploits the visual/motor channel of communication and relies upon social mediation for student achievement. Because blind students cannot partake of the visual channel of communication and are often socially isolated, they generally have limited opportunities for incidental learning. This places them at a disadvantage when attempting to participate in classroom activities. Often gaps exist in concept development, making it difficult for classroom teachers to activate prior knowledge, or leading them to make false assumptions in regard to the fundamental understanding these students have of the world around them. Moreover, the need for Braille as a necessary alternative to print creates a challenge for general education classroom teachers to provide invaluable corrective feedback, as very few general education classroom teachers can read and write Braille. Lack of eye contact and the impossibility of visually-based social recognition can have a profound impact on a blind student's opportunity to form meaningful and cooperative relationships with peers. Such barriers must be carefully examined and skillfully addressed by practitioners in order to provide genuine and valid access to the general curriculum for blind students.


According to IDEA '97,
Deafness means a hearing impairment that is so severe that [a] child is impaired in processing linguistic information through hearing, with or without amplification, that adversely affects a child's educational performance.

Hearing impairment means an impairment in hearing, whether permanent or fluctuating, that adversely affects a child's educational performance but that is not included under the definition of deafness in this section.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Needs of children who are hearing impaired must take into account factors such as age at onset of disability (in particular, pre-lingual vs. post-lingual deafness), audiometric hearing status (particularly in speech range with amplification), type of hearing loss (conductive, sensorineural, mixed, central) and possible presence of concomitant disabilities. The needs of children who are deaf and children who are hard-of-hearing must be understood as quite distinct when considering communication use. The native language of deaf children is American Sign Language (ASL), but children who are hard-of-hearing may understand speech with amplification and may not identify with members of Deaf culture.

Severity of hearing loss is measured by decibels (dB) or units of loudness. A hearing loss between 15 and 20 dB is considered slight. A person with a hearing loss of 60 dB has difficulty hearing conversational speech without amplification. An individual with a hearing loss of 100 dB is not able to hear a power lawnmower without amplification (Kirk, Gallagher, & Anastasiow, 2000).

Children and adults with hearing disabilities characteristically confront significant issues with regard to social and intellectual development, speech and language development, and educational achievement. Reviews of the research on intellectual characteristics of children with a hearing impairment suggest that distribution of intelligence or IQ scores is similar to their hearing counterparts (Gargiulo, 2003.) Any difficulties in performance appear to be closely related to speaking, reading, and writing the English language, but not to level of intelligence (Paul & Quigley, 1990). Children who are identified as deaf and taught a sign language before the age of two perform much better on all tasks than those identified after reaching age two Kirk et al., 2000).

For those with a hearing impairment, particularly children who are born deaf, speech and language skills are the areas of development most severely affected. The majority of deaf children have a very difficult time learning to use speech (Gargiulo, 2003; McLean, Bailey, & Wolery, 1996); children who are deaf exhibit significant articulation, voice quality, and tone discrimination difficulties—even babies who are deaf, whether born deaf or becoming deaf as early as 8 months of age, appear to babble less than their hearing peers (Allen & Schwartz, 1996; Gargiulo, 2003).

Two main ways in which students with hearing impairments communicate are through oral means (by speech or lip-reading) and manual means (sign language) (Wood, 2002). Students who communicate through manual methods use the American Sign Language (ASL) system. This is a system of hand and arm movements, positions, and gestures that translate spoken words into visual representations. If parents do not help their child(ren) form gestures that are part of the standard ASL lexicon, they may develop their own sign system, called 'home sign' (Kirk, et al., 2000).

Social and emotional development for hearing-impaired children depends heavily on their ability to use communication skills. In a classroom setting, students with hearing impairments may have difficulty following simple directions; may use impaired or unclear speech; may be more attentive to faces than to other informational cues during conversation; may avoid situations that require talking and listening; may be very sensitive to bright colors and objects; may be very aware of any change in décor; may have unusual reactions to loud, dull noises; may respond to vibrations of low-flying airplanes or heavy trucks; and may seem shy and withdrawn from other children (Wood, 2002). All of these behaviors can interfere with optimal social and emotional development.

Classroom teachers routinely exploit the auditory-vocal channel of communication during instruction. This heavy reliance upon speaking and listening in a typical classroom limits access to the general curriculum for deaf students. Since ASL is the native language of the Deaf, students who have never had the benefit of hearing English language are notably challenged in learning written English as a second language, particularly in the areas of Language Arts and other literacy areas. This challenge is exacerbated by the lack of correspondence between written English and American Sign Language, as ASL has its own distinctive form or syntax which does not match that of English. In addition, many of the subtleties and nuances of English are ordinarily discovered through social interactions; without conversational facility and direct access to spoken English, deaf students are at a distinct disadvantage in accessing the components of the general curriculum that rely on reading and understanding English.


According to IDEA '97,
Deaf-blindness means concomitant hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that cannot be accommodated in special education programs solely for children with deafness or children with blindness.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

The federal definition of deaf-blindness stresses its uniqueness as contrasted with deafness or blindness. Apart from the uniqueness of deaf-blindness in and of itself are various ways in which the disability manifests itself. For example, Rubella syndrome may produce a sensorineural hearing loss and congenital cataracts, but may also result in central nervous system dysfunctions and cardiac problems. Ushers syndrome initially appears as a profound hearing loss and in adolescence results in loss of peripheral vision. CHARGE syndrome adds yet other physical and intellectual dimensions to visual and hearing challenges. When considering the needs of these students, age at onset, progression of sensory loss, and severity of sensory impairment must all be carefully examined.

Classroom inclusion is extremely challenging for students who are deaf-blind. A combination of vision and hearing impairment limits use of auditory/vocal and visual/motor channels of communication. Lack of opportunity to move about freely and to communicate can result in extreme isolation. Except for students with sufficient residual vision and hearing, it is difficult to view the typical classroom as providing a least restrictive environment for students who are deaf-blind, as substantial supports for mediating the social, communication, and mobility needs of students who are deaf-blind must be carefully planned and implemented for curriculum access and participation to occur.

Significant Developmental Delay

According to IDEA '97,
Mental retardation means significantly sub-average general intellectual functioning, existing concurrently with deficits in adaptive behavior and manifested during the developmental period, that adversely affects a child's educational performance.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Here, significant developmental delay refers to a subgroup of IDEA's category of mental retardation. Individuals with significant developmental delays require greater intensities of supports than the majority of students with mental retardation.

Historically, children with mental retardation (MR) made up the largest special needs population. Today, MR is understood from many different perspectives. By definition, people who are mentally retarded demonstrate significant sub-average performance on standardized tests of intelligence. Intelligence is commonly understood as an underlying quality or trait inferred from behavior observed to be "smart." When measured as IQ, this trait is seen as a quantity that increases with age and levels off with maturity. Debate exists over this construct of intelligence, resulting in controversy over its measurement, mutability, plasticity, and structure.

The percentage of children identified as mentally retarded has declined over the years as eligibility according to IQ shifted from one to two units of standard deviation, effectively eliminating 13% of otherwise qualified cases under the normal curve. The permanence of mental retardation has been challenged in recent history as well. In 1992, the American Association on Mental Retardation (AAMR) proclaimed that individuals who overcome deficits in adaptive behavior might no longer be considered mentally retarded despite their performance on standardized tests of intelligence. According to the U.S. Department of Education's Office of Special Education Program's (OSEP) 22nd Annual Report to Congress—

Prior to the passage of P.L. 94-142, the educational prospects for children with disabilities were bleak. This was particularly true for children with mental retardation and other severe developmental disabilities, many of whom were institutionalized. Today most of those children can expect to live at home, and many receive special education and related services in regular schools. For example, by 1997–98, just 8% of children with significant developmental disabilities1 were served in separate schools or in residential facilities.

Mental retardation, also known as developmental disability or significant cognitive impairment, can be viewed from a variety of perspectives but always involves limited cognitive capacity. Cognitive capacity can be understood in terms of degrees of severity or levels of intensities of supports necessary to live independently in natural or assisted environments. Of particular importance is the context in which deficits in adaptive behaviors become manifest. That is, what are the functional or whole-life consequences of mental retardation?

Again, the needs of students identified as mentally retarded vary according to many factors. In general, the greater the severity or limitations of a disability, the greater the emphasis has been on developing functional and life skills rather than setting more academic goals. Hallahan and Kaufman (2002), Heward (1996), and Hunt (1999) have discussed readiness skills and functional academics as curriculum goals, emphasizing the acquisition of those skills that can be used in everyday home, community, and work environments. According to Matson (1990), the presence of deficits in independent living skills should be a focus of active teaching to promote independent living. A focus on adaptive skills fosters self-reliance.

Colette and Tompkins (1999) recommend focusing on the critical environment in which a student is expected to function and identifying those specific skills or activities deemed necessary for a student to participate more successfully in those identified environments. Colette and Tompkins also emphasize the importance of addressing the social and emotional needs of students who are mentally retarded. Students often need assistance with focusing simultaneously on multiple social cues and in selecting appropriate social strategies. Improving social-perception and strategy-generation skills in these students is critical. Many agree that specialized instruction in the area of social cognitive processes is needed to prepare these students to successfully adapt to a dynamic and increasingly diverse social environment. Because of their cognitive limitations, some students with mental retardation may continue to require a high degree of on-the-spot direction from teachers or peers regarding how to interpret or respond to specific social situations (Leffert, Siperstein, & Millikan, 2000). A focus on executive control, self-direction, and transfer/generalization of skills and strategies is often necessary (Sands, 2000). Turnbull (et al., 2002) and Heward (1996) stress the need for a strong sense of self-determination, personal development, and access to leisure and travel to improve quality of life for these students.

The low-incidence aspect of mental retardation concerns individuals who depart extremely from the norm in terms of general intellectual functioning. These are students who have an intensive need for support, may also have complex health issues, and require a substantially modified curriculum. Effective progress for these students requires a blending of expanded or augmented curricular options with appropriate entry points in the various domains making up the general education curriculum. Several models (see What planning models are in use for students with low-incidence disabilities? for discussion) exist for planning this blending of curriculum content options for students with significant developmental delay. The main challenge is to build a system of services and supports for implementing instruction while at the same time imparting the value of self-determination and self-reliance so that skills acquired will transfer into real-world community settings.

Significant Physical and Multiple Disabilities

According to IDEA '97,
Orthopedic impairment means a severe orthopedic impairment that adversely affects a child's educational performance. The term includes impairments caused by congenital anomaly (e.g., clubfoot, absence of some member, etc.), impairments caused by disease (e.g., poliomyelitis, bone tuberculosis, etc.), and impairments from other causes (e.g., cerebral palsy, amputations, and fractures or burns that cause contractures).

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Subsumed under this heading are students who fall under IDEA '97's categories of orthopedic impairments and multiple disabilities.

As this definition suggests, students with orthopedic impairments may vary considerably in the nature and severity of their disabilities. Many orthopedic impairments do not limit students' academic performance (Sherrill, 1993). However, the age at which a disability occurs, its underlying cause, and the presence of secondary disabilities (if any) may affect a student's need for special education and related services. For example, the age at onset of a disability and the suddenness with which it occurred may affect a student's adjustment. Students whose disabilities occur or develop when they are children may miss valuable opportunities for social development through play with same-age peers. Students with orthopedic impairments resulting from disease may have ongoing health concerns that affect their educational performance (Dunn, 1997).

According to IDEA '97,
Multiple disabilities means concomitant impairments (such as mental retardation-blindness, mental retardation-orthopedic impairment, etc.), the combination of which causes such severe educational needs that they cannot be accommodated in special education programs solely for one of the impairments. The term does not include deaf-blindness.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Significant physical and multiple disabilities represent a highly heterogeneous body of students with vastly different yet overlapping needs. The need for medically-related assistance and supports are common among these students. The extent to which highly technical and intensive supports can be effectively provided in local public schools raises questions about the appropriateness of inclusive programming for this group. Still, some children with orthopedic impairments, whose educational opportunities were formerly restricted to home instruction or hospital settings, may now participate fully in general education classroom activities with the removal of architectural barriers that were once commonplace in traditional classrooms and school buildings.

For example, children with severe forms of cerebral palsy, a neuromuscular orthopedic condition, may present very intensive special needs requiring technology, multidisciplinary service delivery, and medical assistance. Children with multiple disabilities may also present complex medical and health-related issues. They may have severe cognitive challenges in combination with sensory and motor disabilities.

The needs of children with significant physical and multiple disabilities vary widely. Students with a simple physical disability such as a missing limb will be very easy to include in a general educational setting with basic technical help, perhaps including a prosthesis and adaptive training; while a student who has cerebral palsy and is also blind presents a much greater challenge to inclusion. Obviously, the physical environment of a classroom and school may need to be modified to allow for accessibility and the opportunity for a student to develop independence (Lewis, 1999; Heward, 1996). Students may need specialized and/or adapted equipment to enhance or maximize use of their skills. Often a student's family needs to learn how to care for them at home and how to access services and other resources available to aid in daily living. A student's family also often needs information regarding available treatments and service options (Colette, 1999). Again, the degree to which these and other supports are required varies widely depending on the exact extent and nature of a student's disability(ies).

To the extent possible, physical and emotional independence, autonomy, and self-advocacy are desirable goals (Hallahan & Kauffman, 2000). Students may need help in developing a satisfactory level of self-esteem (Wood, 1997). Students with multiple physical disabilities may need cognitive, communicative, and affective assistance and strategies to reach their greatest potential (Sands, 2000). Academic growth may require adapted instruction to meet their needs, as well as career education and life-skills training (Heward, 1996; Lewis, 1999). Teachers and other personnel who work with these students need to maintain open communication with their families and notify them of changes in attention or in physical and intellectual functioning (Wood, 1997).

Autistic Spectrum

According to IDEA '97,
Autism means a developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age 3, that adversely affects a child's educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. The term does not apply if a child's educational performance is adversely affected primarily because the child has an emotional disturbance, as defined in paragraph (b)(4) of this section.

A child who manifests the characteristics of "autism" after age 3 could be diagnosed as having "autism" if the criteria in paragraph (c)(1)(i) of this section are satisfied.

Authority: 20 U.S.C. 1401(3)(A) and (B); 1401(26)

Today, autism is understood not as a single condition but as a spectrum of pervasive developmental disorders (PDDs) that include classic autism, Asperger's syndrome (autism in individuals without language delay or intellectual disability), and Rett syndrome (degenerative disorders leading to autism), among others (Dempsey & Foreman, 2001). Most individuals with autism display significant impairments in communication, daily living skills, and social skills. Approximately 75% of autistic individuals function on a retarded level with cognitive ability closely paralleling their level of autism (Waterhouse & Morris, et al., 1996). Main characteristics of autism include deficits in social interaction, language, and play, and deficits in behavior manifested as self-stimulatory behavior and/or perseverance with a narrow range of routines or interests (Dempsey & Foreman, 2001).

Wood (1997) discusses the need for auditory training and controlled exposure to sensory experiences to reduce averse reactions to sensory stimuli among some students with autism. Others discuss the need for life skills and vocational preparation, focusing on work habits and responsibilities (Turnbull, et al., 2002; Hunt & Marshall, 1999). Still others stress the need for functional academics that will allow children with autism to develop skills that are useful in daily life (Heward, 2002; Turnbull, et al., 2002). In addition, Colette and Tompkins (1999) state that families of children with autism may need individualized programs to help them best meet the needs of their child.


Considering Generic Needs

Thus far, we have discussed the needs of students with low-incidence disabilities as they have been defined by IDEA category and then subsumed under broader headings or clusters. Traditionally, understanding of the needs of students with disabilities originated from a medical or deficit model. IDEA has since transformed this interpretation of needs into a more functional/educational model. For example, blindness and deafness are not defined by sensory acuity but rather by observing functional and educational implications of sensory impairments. By observing the discrepancy(ies) between the demands of an educational setting and a student's functional capabilities, the impact of a disability can be clinically derived. For students with more severe or multiple disabilities, a procedure known as developmental diagnosis was originally employed in which observed behaviors of students were compared with norms obtained across various developmental domains (Stephens, 1971). Developmental schedules contain sequences of skills that normally appear in order. Once a student's developmental level was established, targets for instruction were then selected and prioritized based on the next, unattained developmental milestone.

This bottom-to-top approach proved painstakingly slow. By the late 1980s it was feared that students would be "aging out" of special education programs without the necessary skills to transition to the world of work and daily life (Will, 1986). Ecological assessment soon took precedence over developmental diagnosis as a tool for determining needs of students with severe and complex disabilities. Referencing behaviors against the requirements of independent functioning in real contexts yields far more practical and functional targets on which to focus instruction. Such an approach begins with desired outcomes and indicators of high-quality living. Understanding need from such a perspective focuses less on unique deficits and more on needs held in common. Needing a place to live, work, and participate in society to the maximum extent possible represents a desired set of outcomes for such an approach. The discussion of curriculum and teaching strategies that follows reflects this perspective that while students who have low-incidence disabilities often have unique needs, they also hold much in common.


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Last Updated: 11/05/2010

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