Disability: Defintion and Classification

Background on Disability

Disability is complex, dynamic, multidimensional and contested (World Health Organization, 2011). Understanding the nature of disability and their circumstances is substantial for these can improve efforts to remove disabling barriers and provide services to allow people with disabilities to participate. For the context of the present study, the succeeding discussion offers the manifold definitions of disability across legal, medical and psycho-social standpoints. It presents categorical definitions of specific disabilities and how are these characteristics be given consideration in identifying persons with disabilities and their eligibility for special education services. 

Over the years, disability has been defined by various sectors due to the increasing progress in disability movements, legislation and research. In these definitions, two perspectives emerge as to what constitutes disability. The first is the medical model of disability which assumes disability as a biological fact, a condition which moves away from normal physical, cognitive and/or psychological functioning, resulting in reduced opportunities and quality of life. The second is the social model of disability, which views disability as a social construct, that the challenge of disability is not exclusively credited to a condition, but rather from the social and environmental barriers which omit persons with disability from full participation in society. However, the World Health Organization (2011) stresses that disability should not be viewed as purely medical nor purely social. Though society can contribute to handicapping conditions, persons with disabilities also experience difficulty because of their physical/health condition. For this reason, the World Health Organization adopted a “bio-psycho-social” model”. This model defines functioning and disability as a dynamic interaction between health (or physical) conditions and contextual factors, both personal and environmental (International Classification of Functioning, UNESCO, 2001).

Hence, considering this bio-psycho-social model, a person with physical impairment who depends on a wheelchair for mobility and who goes to a school without ramps and/or accessible sanitation facilities clearly has a disability as a result of the environmental barriers s/he faces. However a child who is blind and has access to books and other learning materials in Braille, educational support through itinerant resource teachers, and a school that is welcoming, inclusive and accessible for all children has impairment, does not necessarily has a disability because s/he faces no environmental and attitudinal barriers (UNESCO, 2009).

Moreover, various legislations enacted for the past years have provided definitions of disability. This is done to recognize individuals eligible for special education and related services as well as to protect these individual’s rights against discrimination.

In particular, the Americans with Disabilities Act defined a person with disability as: (1) having a physical or mental impairment that substantially limits him or her in some major life activity, and (2) having experienced discrimination resulting from their physical and mental impairment (Boyle and Scanlon, 2010).

Individuals with Disabilities Education Act on the other hand defined the term "child with a disability" means a child: "with mental retardation, hearing impairments (including deafness), speech or language impairments, visual impairments (including blindness), serious emotional disturbance, orthopedic impairments, autism, traumatic brain injury, other health impairments, or specific learning disabilities; and who, by reason thereof, needs special education and related services”. This definition includes specific disability terms, which are also defined by IDEA and be later defined in this chapter.

In the Philippines, persons with disabilities are defined as follows (Japan International Cooperation Agency, 2002):

As defined by Batas Pambansa No. 344:

“those suffering from restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being as a result of a mental, physical, or sensory impairment.”

As defined by the Economic Independence of Disabled Persons Act:

“persons who cannot perform work in the usual and customary way due to loss of limbs or any part of the body by injury or absence thereof by birth.”

As defined by Republic Act 7277 (Magna Carta for Persons with Disabilities):

“those persons suffering from restrictions from different abilities as a result of a mental, physical, and sensory impairment, to perform an activity in the manner or within the range considered normal for a human being.”

The term “disability” is most often used interchangeably with the terms “impairment” and “handicap”. To differentiate each of these terms distinctively, the World Health Organization revised and currently defines the words “impairment”, “disability”, and “handicap” as the following (International Classification of Functioning, World Health Organization, 2001):

Impairment is a loss or abnormality in body structure or physiological function (including mental functions). Abnormality here is used strictly to refer to a significant variation from established statistical norms (i.e. as a deviation from a population mean within measured standard norms) and should be used only in this sense.

Disability is an umbrella term for impairments, activity limitations and participation restrictions. It denotes the negative aspects of the interaction between an individual’s health condition and contextual factors (environmental and personal factors).

Handicap is the outdated term for what is now “participation restrictions”. These are problems an individual may experience in involvement in life situations. The presence of a participation restriction is determined by comparing an individual's participation to that which is expected of an individual without disability in that culture or society.

In grouping or thinking about disabilities, three major schemes are used. These are (a) disability types, (b) severity of the disability, and (c) in terms of incidence, or how often they occur (Bryant, et al, 2008).

Disability Types. This classification utilizes categorical approach in describing disabilities. This approach is the primary way persons with disabilities are identified, are labeled and qualify especially for special education services. The Individuals with Disabilities Act defines thirteen specific disabilities. These are:

(1) Autism. A developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age three, 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.

(2) Deaf-blindness. A concomitant hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that they cannot be accommodated in special education programs solely for children with deafness or children with blindness.

(3) Deafness. A hearing impairment that is so severe that the child is impaired in processing linguistic information through hearing, with or without amplification that adversely affects a child's educational performance.

(4) Emotional Disturbance. A condition exhibiting one or more of the following characteristics over a long period of time and to a marked degree that adversely affects a child's educational performance: , characterized by (a) an inability to learn that cannot be explained by intellectual, sensory, or health factors; (b) an inability to build or maintain satisfactory interpersonal relationships with peers and teachers; (c) inappropriate types of behavior or feelings under normal circumstances; (d) general pervasive mood of unhappiness or depression; and (e) tendency to develop physical symptoms or fears associated with personal or school problems. This includes schizophrenia, but does not apply to children who are socially maladjusted, unless it is determined that they have an emotional disturbance.

(5) Hearing Impairment. 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.

(6) Mental Retardation. This means significantly subaverage general intellectual functioning, existing concurrently with deficits in adaptive behavior and manifested during the developmental period, that adversely affects a child's educational performance.

(7) Multiple Disabilities. Concomitant impairments (such as mental retardation-blindness or mental retardation-orthopedic impairment), the combination of which causes such severe educational needs that they cannot be accommodated in special education programs solely for one of the impairments. Multiple disabilities does not include deaf-blindness.

(8) Orthopedic Impairment. This is a severe orthopedic impairment that adversely affects a child's educational performance. The term includes impairments caused by a congenital anomaly, impairments caused by disease (e.g., poliomyelitis, bone tuberculosis), and impairments from other causes (e.g., cerebral palsy, amputations, and fractures or burns that cause contractures).

(9) Other Health Impairment. This means having limited strength, vitality, or alertness, including a heightened alertness to environmental stimuli, that results in limited alertness with respect to the educational environment, that (a) is due to chronic or acute health problems such as asthma, attention deficit disorder or attention deficit hyperactivity disorder, diabetes, epilepsy, a heart condition, hemophilia, lead poisoning, leukemia, nephritis, rheumatic fever, sickle cell anemia, and Tourette syndrome; and (b) adversely affects a child's educational performance.

(10) Specific Learning Disability. A disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, that may manifest itself in the imperfect ability to listen, think, speak, read, write, spell, or to do mathematical calculations, including conditions such as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. This does not include learning problems that are primarily the result of visual, hearing, or motor disabilities, of mental retardation, of emotional disturbance, or of environmental, cultural, or economic disadvantage.

(11) Speech or Language Impairment. A communication disorder, such as stuttering, impaired articulation, a language impairment, or a voice impairment, that adversely affects a child's educational performance.

(12) Traumatic Brain Injury. An acquired injury to the brain caused by an external physical force, resulting in total or partial functional disability or psychosocial impairment, or both, that adversely affects a child's educational performance. Traumatic brain injury applies to open or closed head injuries resulting in impairments in one or more areas, such as cognition; language; memory; attention; reasoning; abstract thinking; judgment; problem-solving; sensory, perceptual, and motor abilities; psychosocial behavior; physical functions; information processing; and speech. Traumatic brain injury does not apply to brain injuries that are congenital or degenerative, or to brain injuries induced by birth trauma.

(13) Visual Impairment including Blindness. This is impairment in vision that, even with correction, adversely affects a child's educational performance. The term includes both partial sight and blindness.

However, this categorical approach does more harm than good according to some parents, educators and groups (Allen and Cowdery, 2005). They argue that individuals, particularly the very young ones, may get locked into categories or put into programs that compound the child’s delay. The danger of the stigma, the label and the stereotype a certain category hold could also greatly affect the person categorized in a particular disability. Labeling students seems to imply that the student with disability is the cause of educational problem rather than the education’s system limitations (Waldron, 1996). Nevertheless, categorizing helps, primarily educators, to understand and effectively meet the person with disabilities’ needs. The more specific their understanding is, the more specific their intervention can be (Wilmshurst and Brue, 2010).  It also paved the way to the development of specialized teaching methods, assessment approaches, and behavioral interventions for each of the specific disability.

Severity of the Disability. This is a non-categorical approach where persons with disabilities are grouped by the severity (mild, moderate, severe) of their problems not by disability (Bryant et al, 2008). This considers how the condition influences an individual’s performance. For example, individuals with mild disabilities need some accommodation while those with severe disabilities need thorough support and assistance for an extensive period of time.

In grouping disabilities according to severity, it has to be noted that no disability is more severe than the other. All disabilities are serious and the effect on the person with disabilities including their families should never be underestimated. Also, each disability grouping falls along a continuum of severity from mild to severe. It is therefore improper to think that all learning disabilities are mild (Bryant et al, 2008).

Incidence. A non-categorical approach in which disabilities are grouped according to how often they occur: high-incidence or low-incidence disabilities. High-incidence disabilities include learning disabilities, speech language impairment, health impairments, mental retardation and emotional/behavioral disorder. Low-incidence disabilities on the other hand consist of autism, multiple-severe disabilities, developmental delays, deaf and hard of hearing, visual disabilities, physical disabilities and traumatic brain injury (Mastropieri and Scruggs, 2000; Bryant, et al, 2008).

This grouping scheme in grouping disabilities contends that dealing with more common disabilities should be different from less frequent or low-incidence disabilities. The less commonly occurring disabilities often require specialized services from a multidisciplinary team of professionals. In addition, this grouping is of use when the issue at hand for students with disabilities centers on the provision of services, the availability of qualified personnel and the technical assistance needed in important resources (National Center on Accessible Instructional Materials, 2010). 

Nowadays, both categorical and non-categorical approaches in grouping disabilities are used. For instance, individuals with disabilities qualify for special education by being determined as having a specific disability. Schools then usually serve these individuals in line with their needs and performance.