Identification andAssessment of Studentswith DisabilitiesDaniel J. Reschly

Abstract

Students with disabilities or suspected disabilities are evaluated by schools to deter-mine whether they are eligible for special education services and, if eligible, to deter-mine what services will be provided. In many states, the results of this evaluation alsoaffect how much funding assistance the school will receive to meet the students spe-cial needs.

Special education classification is not uniform across states or regions. Students withidentical characteristics can be diagnosed as disabled in one state but not in anotherand may be reclassified when they move across state or school district lines.

Most disabilities with a clear medical basis are recognized by the childs physician orparents soon after birth or during the preschool years. In contrast, the majority of stu-dents with disabilities are initially referred for evaluation by their classroom teacher(or parents) because of severe and chronic achievement or behavioral problems.

There is evidence that the prevalence of some disabilities varies by age, the high-inci-dence disabilities such as learning disabilities and speech-language disabilities occurprimarily at the mild level, the mild disabilities exist on broad continua in which thereare no clear demarcations between those who have and those who do not have the dis-ability, and even mild disabilities may constitute formidable barriers to academicprogress and significantly limit career opportunities.

Problems with the current classification system include stigma to the child, low relia-bility, poor correlation between categorization and treatment, obsolete assumptionsstill in use in treatment, and disproportionate representation of minority students.Both African-American and Hispanic students are disproportionately represented inspecial education but in opposite directions. The disproportionately high number ofAfrican Americans in special education reflects the fact that more African-Americanstudents than white students are diagnosed with mild mental retardation. Thoughpoverty, cultural bias, and inherent differences have been suggested as reasons for thisdisproportionate representation, there are no compelling data that fully explain thephenomenon.

In most states, classification of a student as disabled leads to increased funding fromthe state to the school district. This article suggests a revised funding system thatweights four factors (number of deficits, degree of discrepancy, complexity of inter-vention, and intensity of intervention) in a regression equation that would yield a totalamount of dollars available to support the special education of a particular student.

4040

The Future of Children SPECIAL EDUCATION FOR STUDENTS WITH DISABILITIES Vol. 6 No. 1 Spring 1996

Daniel J. Reschly, Ph.D.,is distinguished profes-sor in the departmentsof Psychology and Pro-fessional Studies inEducation at Iowa StateUniversity.

41

Identification andAssessmentPurposesThe two main purposes of identification andassessment of students with disabilities are todetermine whether they are eligible for spe-cial education services and, if they are eligi-ble, to determine what those services will be.

Eligibility for special education servicesrequires two findings: first, the student mustmeet the criteria for at least one of the thir-teen disabilities recognized in the federalIndividuals with Disabilities Education Act(IDEA) or the counterparts thereof in statelaw,1,2 and second, special education and/orrelated services must be required for the stu-dent to receive an appropriate education.2,3It is true that some students are eligible forspecial education and/or related servicesbut do not need them, while other studentsneed the services but are not eligible accord-ing to federal or state classification criteria.

If the disability diagnosis and special edu-cation need are confirmed, the student thenhas certain important rights to individualizedprogramming designed to improve educa-tional performance and expand opportuni-ties. These rights are established through sev-eral layers of legal requirements based onfederal and state statutes, federal regulations,state rules, and state and federal litigation.2

Chief among these rights are the require-ments that eligible students with disabilitiesmust receive an individualized educational

program (IEP) based on needs identified inan individualized, full, and complete evalua-tion. The needs identified during the evalu-ation form the basis for the students per-sonal and educational goals, the speciallydesigned instruction and related services(for example, psychological consultation orphysical therapy), and the methods to evalu-ate progress toward the students goals.

The classification system used in specialeducation identification also serves numer-ous other functions that are not discussedhere (for example, organization of research;communication among scholars, lay public,and policymakers; differential training andlicensing of specialists such as special educa-tion teachers; and advocacy for expandedrights and support for programs).

Current PracticesA number of comprehensive classificationsystems exist and influence, to varyingdegrees, classification in special educa-tion.46 There is, however, no official specialeducation classification system that is useduniformly across states and regions. For sta-tistical purposes, students are classified bytheir primary disability, though it is notunusual for a student to have disabilities inmore than one category.

Federal and State Disability CategoriesThirteen disabilities are briefly defined inthe federal IDEA regulations: autism, deaf-blindness, deafness, hearing impairment,mental retardation, multiple disabilities,orthopedic impairment, other health

Identification of students for special education placement serves multi-ple purposes that have direct and indirect benefits as well as risks. In thisarticle, current special education identification, classification, andassessment practices are described and evaluated in light of emerging con-cerns about their reliability, usefulness, and fairness. Alternatives to conven-tional practices are discussed.

42 THE FUTURE OF CHILDREN SPRING 1996

impairment, serious emotional distur-bance, learning disability, speech or lan-guage impairment, traumatic brain injury,and visual impairment. Federal law doesnot provide classification criteria for any ofthese disabilities except learning disability.1

These disability categories are based tovarying degrees on eight dimensions ofbehavior or ability: intelligence, achieve-ment, adaptive behavior, social behavior andemotional adjustment, communication/lan-guage, sensory status, motor skills, andhealth status.7 About 90% of the studentswho are found eligible for special educationhave disabilities that fall primarily within thefirst five of those dimensions.

Although all states must provide specialeducation to all students with disabilities,states may or may not adopt the disability cat-egories recognized in the federal regula-tions. In fact, there are significant differencesacross the states in the categorical designa-tions, conceptual definitions, and classifica-tion criteria.8,9 These differences have their

greatest impact on the students who will bedescribed later as mildly disabled. It is entire-ly possible for students with identical charac-teristics to be diagnosed as disabled in onestate, but not in another, or to have the cate-gorical designation change with a moveacross state or school district lines.

The category of mental retardation(MR)10 illustrates the diverse classificationpractices in special education. The IDEAregulations define mental retardation assignificantly subaverage general intellectu-al functioning existing concurrently withdeficits in adaptive behavior.1 Mental retar-dation has been recognized as one of thedisabilities for which special educationwas provided throughout this century.6,11Despite the longevity and nearly universalrecognition of this category, enormous dif-

ferences exist among states in terminology,10key dimensions (for example, some statesdo not include adaptive behavior in the con-ceptual definition), and classification crite-ria (for example, the intelligence quotient[IQ] ceiling for this category varies from69 to 85). The variations in criteria have themost effect on the mild level of mental retar-dation. Similar variations among states existfor other disability categories, especially seri-ous emotional disturbance (SED), learningdisability (LD), and speech or languageimpairment (SP/L).

Medical and Social System ModelsHistorically, the special education classifica-tion system involved a mixture of medicaland social system models of deviance.79 Theleast ambiguous disabilities are the clearlymedical disabilities (such as visual impair-ment or orthopedic disabilities), often rec-ognized by the childs physician soon afterbirth or during the preschool years. In con-trast, the disabilities defined by social systemmodels represent behavior, intelligence,communication abilities, or other character-istics that deviate significantly from thenorm, and which are generally diagnosedduring the school years (see Table 1). Theinitial identification of a student with socialsystem disabilities usually occurs because of ateacher-initiated referral of the child as aresult of severe and chronic achievement orbehavioral problems.7

In the social system model, the questionof where to draw the line between normaland significantly different characteristicsis somewhat subjective, and has properlybeen considered a matter within the discre-tion of local or state authorities. (See thearticle by Parrish and Chambers in this jour-nal issue.) In addition, knowledge about thepossible underlying physical causes of somesocial system disabilities (such as learningdisabilities and attention-deficit disorder) ischanging rapidly. There is research linkingbiological factors to mild disabilities such aslearning disability, and in particular readingdisabilities. (See the article by Lyon in thisjournal issue.) These links involve possibledifferences in brain functions among read-ers with and without disabilities as well as apossible genetic link to severe reading dis-abilities. The differences are, however, cor-relational as noted by a writer in a recentScience News and Comment.12 Further

The paucity of clear evidence of a medicalbasis for many disabilities and the factthat most disabilities are at the mild leveldoes not diminish the importance of earlyrecognition of problems.

43Identification and Assessment of Students with Disabilities

research is needed to determine (1) if thesebiological correlates are replicated with newsamples of students with learning disability;(2) whether the presence or absence of thecorrelates reliably distinguishes betweenthose with and without learning disability;and (3) whether treatments work different-ly depending on the presence, amount, andkind of biological correlates. Until thesequestions are answered, little practical utili-ty exists for the research on the biologicalcorrelates of learning disability.

Mental retardation is perhaps the clearestexample of the mixture of medical and socialsystem models. The current prevalence ofmental retardation among school-age chil-dren and youth is 1.1%.13 Approximatelyone-half of these persons have moderate tosevere disabilities (IQ below 55) character-ized by identifiable anomalies (such asDowns Syndrome) that are the cause oftheir significantly lower performance inadaptive behavior and intelligence.6,11 A sec-ond group of persons with mental retarda-tion who typically perform at the mild level(IQ about 55 to 70 or 75) do not exhibit anybiological anomalies that can be posited asthe cause of their lower performance.14,15Indeed, the etiology of this form of mentalretardation has been called cultural-familialor psychosocial as a means of acknowledging

that social system factors may be preemi-nent.16 Persons with mild mental retardationrather than moderate or severe mental retar-dation have markedly different levels andpatterns of educational needs and adultadjustment. Unfortunately, the current clas-sification system uses the same term to referto both groups of persons,5 leading to fre-quent confusion over what mental retarda-tion means and unnecessary stigmatizationof persons with mild mental retardation.6

The paucity of clear evidence of a med-ical basis for many disabilities and the factthat most disabilities are at the mild level(see later discussion) does not diminish theimportance of early recognition of prob-lems and the implementation of effectivetreatments. For example, problems withattaining literacy skills as reflected in verylow reading achievement or poor behav-ioral competencies as reflected in aggressivebehaviors often interfere significantly withnormal development and seriously impairthe individuals opportunities to become acompetent, self-supporting citizen.

Distribution and Severity ofDisabilitiesIn understanding the distribution and severi-ty of disabilities, it is important to remember

Characteristic Medical Model Social System Model

Definition of problem Biological anomaly Discrepancies between expected and observed behavior in a specificcontext

Focus of treatment Focus on cause with purpose Eliminate symptoms through directof curing or compensating educational or behavioral interventionsfor underlying problem

Initial diagnosis In preschool years by medical During school-age years by professionals professionals in education or psychology

Incidence Low (about 1% of school-age High (about 9% of school-agepopulation) population)

Prognosis Life-long disabilities Disabilities may be recognizedofficially only in school years

Cultural context Cross-cultural Arguably, culturally specific

Comprehensiveness Usually affects performance in May affect one or a few roles in most roles in most contexts a few or multiple contexts

Table 1

Comparison of Medical and Social System Models of Disabilities

44 THE FUTURE OF CHILDREN SPRING 1996

that (1) the prevalence of disabilities varies byage and category, (2) the high-incidence dis-abilities such as learning disability and speechor language impairment occur primarily atthe mild level, and (3) even mild disabilitiesmay constitute formidable barriers to attain-ing adult goals such as a high-status career.

From the summary of disabilities by cate-gory for children ages 611 and 1217 pro-vided in Table 2, several trends are apparent.Learning disability is the most frequentlyoccurring disability at both age intervals, atrend that is particularly prominent at the1217 age interval. The prevalence ofspeech and language disabilities declinessubstantially with increasing age. Also,although there are 13 categories, more than90% of the children classified as disabled inschool settings are accounted for by learningdisability, speech or language impairment,mental retardation, and serious emotionaldisturbance. (See the Child Indicators arti-cle by Lewit and Baker in this journal issuefor a discussion of changes in the prevalenceof learning disability and mental retardationsince the inception of Public Law 94142.)

The severity of disabilities also varieswithin categories. Severity is influenced by

(1) the size of the deficit in behavior or skills;(2) the number of areas in which there aredeficits; and (3) the amount and kind of sup-port needed to participate in daily activitiessuch as learning, work, leisure, self-care, andmobility in the community. Persons with dis-abilities at a severe level typically have largedeficits, often in two or more areas, thatrequire extensive and consistent support.Persons with disabilities at the mild level typ-ically have smaller deficits on the key dimen-sions, deficits in fewer areas, and can func-tion without assistance in most of the normaldaily activities.

Knowledge of the exact distribution ofseverity within disability categories isextremely limited. In broad terms, however,it appears that the majority of students diag-nosed with learning disability and speech orlanguage impairment have disabilities at themild level. The level of disabilities in mentalretardation and serious emotional distur-bance can vary from mild to severe; however,at least half are at the mild level.17,18

As noted earlier, the distinction betweendisability and normal ability/behavior issomewhat arbitrary and subject to local pref-erences. In particular, the mild disabilities

Percentage of IDEA-Eligible Population PercentageCategory of Overall

6 11 1217 Total Population

Learning disability 41% 63% 51% 5.2%

Speech or language 37% 5% 23% 2.3%impairment

Mental retardation 9% 13% 11% 1.1%

Seriously emotionally 6% 12% 8% 0.9%disturbed

Othera

7% 7% 7% 0.7%

Total 100% 100% 100% 10.25%

aOther includes autism, deaf-blindness, deafness, hearing impairment, multiple disabilities, orthopedicimpairment, other health impairment, traumatic brain injury, and visual impairment.

Table 2

Source: Author using data from Office of Special Education Programs. Implementation of the Individuals with DisabilitiesEducation Act: Sixteenth annual report to Congress. Washington, DC: U.S. Department of Education, 1994, Tables AA6, AA7,AA13, AA14, and AA27.

Percentage of School-Age Population Diagnosedas Disabled by Primary Disability

45Identification and Assessment of Students with Disabilities

exist on broad continua in which there areno clear demarcations between those whohave and those who do not have the disabil-ity. Yet, special education eligibility is adichotomous decision: the student eitheris or is not eligible for services. In manystates, a point or two on discrepancy scores(intended to measure the discrepancybetween a students ability and achieve-ment) can determine whether or not severalthousand additional dollars are spent on thechilds education. Such momentous deci-sions are not supported by our knowledge ofthe distribution curve. One of the key find-ings in the National Institute of Child Healthand Human Development (NICHD)fundedstudies on learning disabilities (see the arti-cle by Lyon in this journal issue) involvesthe impossibility of clearly differentiatingbetween dyslexia (a common learning dis-ability) and low achievement in reading:This study allowed us to investigate thecommonly held belief that dyslexia is a dis-crete diagnostic entity. Our data do notsupport this notion. Rather, they suggestthat dyslexia occurs along a continuum thatblends imperceptibly with normal readingability. These results indicate that no distinctcutoff point exists to clearly distinguish chil-dren with dyslexia from children with nor-mal reading ability; rather, the dyslexic chil-dren simply represent the lower portion ofthe continuum of reading capabilities.19

Finally, the generalizations that a disabili-ty such as learning disability nearly always ismild and that, as adults, persons with learn-ing disability usually are not officially recog-nized as disabled does not mean that milddisabilities are trivial or that they magicallydisappear at age 18 or 21. In fact, studentswith learning disability are seriouslyimpaired in one of the most important devel-opmental tasks in a technologically complexsociety: acquiring literacy skills and usingthose skills to master bodies of knowledge.Poor reading skills in particular constituteformidable barriers to both education andoccupational attainment and significantlylimit adult career opportunities (see the arti-cle by Wagner in this journal issue).

Diagnosis, Classification,and TreatmentElaborate legal requirements govern theprocedures whereby a student is diagnosed

as disabled and placed in special education.The process can be divided into severalstages, each reflecting legally enforceablesafeguards that are designed to ensure thatstudents with disabilities are identified andprovided special education and, at the sametime, nondisabled students are protectedfrom inappropriate placement. The stagesare prereferral, referral, preplacement eval-uation, eligibility determination, IEP devel-opment, determination of the placement,provision of services, annual evaluation ofprogress, and triennial reevaluation.

Progress from prereferral to the provi-sion of services can be interrupted and halt-ed at any one of the stages depending onthe nature of the assessment information,professional judgment, and the decisionsof parents. Informed parental consent isrequired prior to the initiation of the pre-placement evaluation and again prior to the

provision of services. It is at the preplace-ment and triennial reevaluation stages thatdecisions are made about eligibility for ser-vices under the IDEA. See the article byMartin and Martin in this journal issue for adiscussion of the legal requirements andparental and student rights regarding spe-cial education evaluations.

Of all disability categories, mild learningdisability may be the most difficult to diag-nose. Yet, given the prevalence of thisdiagnosis, it is crucial that the process beexamined. Eligibility for learning disabilitytypically involves teacher or parent referralbecause of concerns about achievement lag-ging behind the childs apparent intelli-gence or measured IQ. The evaluation typi-cally includes observation in the regularclassroom, review of the childs educationalhistory including past test scores, assessmentwith standardized tests of achievement andintellectual functioning, determination ifthere are any discrepancies between achieve-ment and intellectual ability, and elimina-tion of other possible causes of the learningproblem (for example, sensory deficits).

Of all disability categories, mild learningdisability may be the most difficult todiagnose.

46 THE FUTURE OF CHILDREN SPRING 1996

In recent years increasing concern hasbeen expressed regarding the dominanceof standardized tests at the expense ofassessment that is related to interventionsin evaluations for learning disability andmild mental retardation. The administra-tion of a comprehensive, individuallyadministered IQ test and one or morestandardized, individually administered

achievement tests nearly always dominatesthe learning disability eligibility process.Such testing is virtually mandated by fed-eral guidelines to establish a severe dis-crepancy between achievement and intel-lectual ability.1

ProblemsProblems with the current classification sys-tem were recognized at least 20 years agoin the large, federally-funded exceptionalchild classification project. Prevalent prob-lems include stigma to the child, poor relia-bility for traditional categories, poor rela-tion of categorization to treatment, obsoleteassumptions still in use in treatment, anddisproportionate representation of minoritystudents.

StigmaThe degree to which lifelong, permanentnegative effects of classification (labeling)occur is disputed. Certainly, the moreextreme claims made in the late 1960s,such as that labels create deviant behaviorrather than vice-versa,20 are heard lessoften now. Nevertheless, the commonnames used for students with mild disabili-ties have negative connotations. An earlier,now classic, review21 reported that there iswidespread misunderstanding of the mean-ings of traditional classifications by bothprofessionals and the lay public;22 and thebearers of labels find the classificationuncomfortable and, very often, objection-able.23 Concerns about the effects of classi-fication on individuals have led to calls forthe elimination of the common classifica-tion categories.24

Although this literature is complex, oneconservative conclusion is that categoricalclassification should be used as sparingly aspossible and, when used, should focus onskills rather than on presumed internalattributes of the individual. Current reformsthat emphasize classification based on thespecific skill deficits (low reading decodingskills) and the services needed (tutoring inphonological awareness) rather than pre-sumed internal attributes may lessen thenegative connotations.

ReliabilityCurrent diagnoses using traditional cate-gories are frequently unreliable. Although itis virtually impossible for a student per-forming at the average level or above to beclassified as learning disabled or mildlymentally retarded, differentiating betweenthese categories or between these categoriesand other classifications such as slow learn-er, economically disadvantaged, and at riskfor poor educational outcomes is often dif-ficult. The reasons for this difficulty include(1) overlapping characteristics among stu-dents in these categories,2527 (2) variationsin teacher tolerance for student diversity(see the article by Hocutt in this journalissue), (3) differences in screening andplacement practices among districts, and(4) variations in the quality of assessmentmeasures used by professionals.28

Researchers19 have noted the diagnosisof dyslexia is not stable for children in theelementary grade levels. The instability fromyear to year further aggravates the reliabilityof the diagnosis of dyslexia, an importantsubcategory of learning disability.

Relation of Classification to TreatmentA disability category is useful to the degreethat it is related to the determination oftreatment, to treatment outcome, and/or toprevention. The information needed todetermine whether or not a student is eligi-ble to be classified as learning disabled, mild-ly mentally retarded, or seriously emotional-ly disturbed typically does not relate closelyto treatment decisions regarding individualgoals, objectives, monitoring of interven-tions, or evaluating outcomes. Furthermore,considerable evidence now suggests that theeducational interventions provided to stu-dents in the different disability categoriesare more alike than different.23,29,30 Effective

Categorical classification should be usedas sparingly as possible and, when used,should focus on skills rather than on pre-sumed internal attributes of the individual.

47Identification and Assessment of Students with Disabilities

instructional programming utilizes the sameprinciples and often the same procedures(intensive individual instruction, along withclose monitoring and feedback) regardlessof whether the student is classified as learn-ing disabled, mildly mentally retarded, seri-ously emotionally disturbed, a slow learner,or educationally disadvantaged.30

Another criterion for usefulness is rela-tion to prognosis or outcomes. The researchhas indicated that traditional categories donot have a demonstrable relationship to spe-cific outcomes or to prognoses.3032

Obsolete Assumption: Homogeneous,Segregated GroupsA subtle, but important, premise of the cur-rent categorical system is that students mustbe classified into categories so that homoge-neous groups can be formed. The efficacyof programming by handicapping condi-tion has been questioned since the 1960sand continues to be a subject of concernwith regard to the current categorical sys-tem.23,29,3133 Many education agencies andpractitioners are moving away from theassumption that student services can bedetermined by category; it is time for thecategorical system to reflect this change inpractice.

Obsolete Assumption: Aptitude byTreatment InteractionPerhaps the most widely accepted tradition-al assumption is that special interventiontechniques, instructional methods, andinstructional materials must be carefullymatched to precisely diagnosed learningstyles or processes. The underlying assump-tion in this matching process was that of anaptitude by treatment interaction (ATI).34The ATI evidence, however, has been uni-formly negative in special education applica-tions using disability categories, modalitypreferences, learning styles, cognitive pro-cessing, or neuropsychologically intactareas.31,33,3538 The process- or style-matchingjustification for the current categorical sys-tem has little empirical support.

Disproportionate Minority PlacementOne of the most controversial aspects of thecurrent system is the disproportionate place-ment of minority students in various cate-gories of disability. Recent data regardingthe participation of various groups of stu-

dents in special education programs aresummarized in Table 3. The data are subjectto differing interpretations; however, theprincipal conclusions are (1) both African-American and Hispanic students are dispro-portionately represented in special educa-tion but in opposite directions, and (2) thedisproportionately high number of AfricanAmericans in special education reflects thefact that more black students than white stu-dents are categorized as having mild mentalretardation. Regardless of the actual propor-tions, there is widespread belief that specialeducation has been used as a dumpingground for minority students.39

Commonly suggested causes of dispro-portionate minority representation in spe-cial education include (1) poverty, (2) dis-crimination or cultural bias in referral andassessment, and (3) unique factors relateddirectly to race or ethnicity. Wagners40analyses implicated poverty as the principalreason African-American students are over-represented in special education. A similarconclusion was published by Reschly41 inan analysis of a large sample of African-American and white students in Delaware

who were classified as learning disabled.However, other studies have produced dif-ferent results, and it cannot be assumedthat poverty is the only, or primary,causative agent. Other factors, such as theincreased prevalence of low birth weightamong African Americans,42 should also beconsidered.

Positive Features of the CurrentClassification SystemThe current categorical system has served as(1) a rallying point for advocacy groups seek-ing support for programs, (2) the structurefor passage of legislation, and (3) the basisfor allocation of monies to establish educa-tional services for students with disabilities.The monumental progress made over thepast 30 years has occurred within the con-fines of the present categorical system.

Considerable evidence now suggests thatthe educational interventions provided tostudents in the different disability categoriesare more alike than different.

48 THE FUTURE OF CHILDREN SPRING 1996

Of All African- Of All Hispanic Of All WhiteAmerican Students, Students, Students,Percentage Who Percentage Who Percentage WhoHave Been Given Have Been Given Have Been Given

Disability This Diagnosis This Diagnosis This Diagnosis

Mild mental 2.1% 0.6% 0.8%retardation

Learning disability 5.0% 4.7% 5.0%

Serious emotional 0.9% 0.3% 0.7%disturbance

Total 8.0% 5.6% 6.5%

Table 3

Source: Author using data from Office of Special Education Programs. Implementation of the Individuals with DisabilitiesEducation Act: Sixteenth annual report to Congress. Washington, DC: U.S. Department of Education, 1994, pp. 198, 201202.

Comparison of Ethnic Representation in Three Categories of Disabilities Based on a 1990 Survey by the Office of Civil Rights

African American Hispanic White

Of the total (disabled 16% 12% 68%and nondisabled) student population in1990 OCR survey, per-centage from eachethnic group

Of students with Mild 35% 8% 56%Mental Retardation,percentage from each ethnic group

Of students with 17% 11% 70%Learning Disabilities,percentage from each ethnic group

Of students with 21% 6% 71%Serious EmotionalDisturbance, percent-age from each ethnicgroup

49Identification and Assessment of Students with Disabilities

Efforts to reform the classification systemneed to provide plausible alternatives thatensure the continued social and politicalsupport for programs needed by studentswith disabilities.

Alternatives to the CurrentSystemThe overall goal of the special education dis-ability classification system should be toenhance the quality of interventions andimprove outcomes for children and youthwith disabilities. At the same time, the cate-gories used should be as free as possible ofnegative connotations, recognizing that nodisability classification system will be totallyfree of negative connotations. This sectionrecommends the development of systemsorganized around the supports and servicesneeded by children and youth, with furtherdesignation, if needed, of the dimensions ofbehavior in which supports and services areprovided.24,43

Dimensional, Not TypologicalClassification systems should be based ondimensions of behavior (reading, social con-duct, and the like) rather than on typologiesof persons. Typologies involving dichotomiessuch as disablednondisabled, retardednotretarded, and learning disablednot learn-ing disabled are never accurate reflectionsof the diversity of student aptitudes andachievement. As discussed earlier, studentsvary on broad continua by fine grada-tions. However, dichotomous decisions areimposed by the current classification system.

Current eligibility rules require educa-tors to decide that virtually identical studentshave very different educational needs. Thesedecisions are inaccurate. What is needed is aclassification system that reflects the realityof student differences. A classification systembased on broad dimensions with fine grada-tions would allow accurate description of thestatus of students without imposing false,eitheror dichotomies.

In the meantime, there is some merit tothe position taken by advocates for the learn-ing disabled, calling for preservation of thefull continuum of services. For the studentdiagnosed with mild learning disability, theschool district, in combination with the par-ents, might be best advised to experimentwith intense interventions (for example,

temporary or long-term placement in a sep-arate classroom), limited intervention (forexample, small-group tutoring two or threetimes a week), or simply a wait-and-seeapproach (for example, no changes atschool but intensive tutoring support fromparents at home) based upon the familyspreferences, the students motivation, andthe results of intervention. When the degreeof disability can be measured but responseto treatment cannot be predicted, the bestchoice may be to offer multiple treatmentoptions.

Functional, Not EtiologicalThe current classification system is based pri-marily on etiology or presumed internalattributes of individuals. These etiologicalformulations are not useful in that they arenot closely related to treatment.

For the vast majority of students nowclassified as mildly disabled, functionalclassification will mean emphasis on skillsrelated to the school academic curricu-lum and to essential social competencies.

K

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Attempts to use functional classificationcriteria and programming have been suc-cessful and represent enormous promisefor improving the current delivery sys-tem.4447 This trend is by no means univer-sal, nor even present in a majority of schooldistricts. Important barriers in the forms offunding mechanisms and disability eligibil-ity criteria exist in most states. However,these impediments have been placedunder careful scrutiny in recent policypapers43 sponsored by the Federal Officeof Special Education Programs.

MultidimensionalAll professionals and parents realize that stu-dents with disabilities are complex humanbeings with a wide range of assets and limi-tations. Unfortunately, the current classifica-tion system suggests that persons with dis-abilities are different from the norm on oneor two salient dimensions such as intelli-gence or achievement. The focus on one ortwo dimensions rather than on the broadrange of assets and limitations often leads toundesirable restrictions of programming to

those dimensions. For example, although itis well known that a significant proportion ofstudents with learning disability have diffi-culties with social skills, or that the adultadjustment of persons with mild mentalretardation will be determined to a greaterdegree by social rather than by academiccompetencies, current educational pro-grams often ignore the vital areas of socialskills and social competencies.48

Reliable TechnologyOver the past 20 years, a reliable technologyhas been developed for direct measurementof student behavior in natural settings.46,4950When an assessment reveals reliable andprecise information about a students devia-tions from the average on relevant dimen-sions, this information can be used in mea-suring the effectiveness of interventions (forexample, assessment of current status inrelation to target objectives, monitoring

progress, and evaluating outcomes). Suchdetailed data on the degree of student vari-ance from the norm could also be used inallocating services to students with the great-est needs, but it should be noted that thisapproach may encourage the assignment oflimited resources primarily to students withthe more severe behavioral problems, givinga lower priority to early intervention for stu-dents whose problems are not yet extreme.

Knowledge Based on EffectiveInterventionClearly, there is a body of knowledge relatedto the effectiveness of instructional interven-tions. Classification systems that focus onfunctional dimensions of behavior will facili-tate the application of that knowledge base.In contrast, a classification system that focus-es on presumed etiology, or on factors suchas underlying neuropsychological processesor learning modalities that have no relation-ship to treatment outcomes, interferes withthe provision of effective treatment.

Components of a ProposedFunding SystemOne of the critical purposes of the currentclassification system involves funding. Classi-fication of a student as disabled producesmarkedly greater educational resources. Avariety of bases for funding additional ser-vices have been discussed for many years.(See the article by Parrish and Chambers inthis journal issue.) The funding system sug-gested below is consistent with the systemreforms described in this article.

Number of DeficitsThe number of deficits exhibited by thestudent could be one of the bases for gener-ation of additional monies. Students with sig-nificant discrepancies over greater numbersof functional dimensions typically requiremore special education services, as well asservices of greater complexity or intensity.However, such a determination should notbe written in stone. Students with a smallernumber of deficits but with persistent prob-lems likely to influence their future employ-ment and other adult goals may benefitfrom intensive services.

Degree of DiscrepancyA second funding variable could be thedegree of discrepancy on each of the

50 THE FUTURE OF CHILDREN SPRING 1996

Attempts to use functional classificationcriteria and programming have been successful and represent enormous promisefor improving the current delivery system.

dimensions in which deficits exist. Larger dis-crepancies typically indicate greater need,requiring greater resources for effective inter-vention. At the same time, this should not beused as a justification for giving low priorityto early intervention for students whose devi-ations from the norm are not yet great.

Complexity of InterventionThe complexity dimension involves at leasttwo components: the skills or competenciesof professionals who work with students andthe need for special equipment or specialenvironments to carry out effective interven-tions. For example, an intervention with astudent exhibiting what now could be calleda behavior disorder might involve the addi-tion of a classroom aide over a period of sev-eral weeks during certain periods of the dayfor the purpose of implementing and moni-toring a behavioral intervention. The cost ofthis intervention may be considerably lessthan an intervention that requires a fully cer-tified teacher with a masters degree workingwith a very small group of students over theentire year.

Intensity of InterventionIntervention intensity includes at least twocomponents: the amount of time requiredto carry out an intervention over a typicalschool day and the length of the interven-tion. Interventions requiring greater intensi-ty should receive more resources than inter-ventions requiring less intensity.

The four funding variables suggestedhere might be regarded as weighting factorsin a regression equation that would yield atotal amount of dollars available to supportthe special education of a particular student.These kinds of analyses, using quite differentvariables, were suggested by Hobbs,51 whonoted that gross categories for funding wereobsolete. The advantages of a funding sys-tem that focused on variables such as num-

ber of deficits over functional dimensions,degree of discrepancies, complexity of inter-ventions, and intensity of interventionscould be a well-integrated classification sys-tem with a consistent philosophy that couldbe implemented at all stages, includingscreening, prereferral intervention, classifi-cation, programming, and funding.

On the other hand, such changes shouldbe accompanied by evaluation of the revisedsystem. The current system has been criti-cized for spending a substantial amount ofspecial educations resources on evaluation.Would the revised system proposed hererequire more or fewer resources for evalua-tion of students? Would it give adequate pri-ority to prevention and early interventionefforts? Would it create unintended incen-tives to classify students in certain ways?These questions should be addressed bythose who implement revised funding andevaluation systems.

ConclusionsClassification reform in special educationhas been discussed for at least two decades.Intractable problems in the current classifi-cation structure shape the delivery systemand detract from the implementation ofeffective interventions for children andyouth with learning and behavior problems.Changes are needed to focus attention oneffective interventions and evaluation ofoutcomes.

The current knowledge base and assess-ment technology supports the developmentof a classification system based on function-al dimensions of behavior and orientedtoward effective educational programming.Application of the available knowledge baseand assessment technology is needed to fur-ther the goal of improving the outcomes ofeducational interventions for children andyouth.

51Identification and Assessment of Students with Disabilities

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