FEATURES OF AUTISM
Autism is a disorder that is present from birth or very early in development that affects essential human behaviors such as social interaction, the ability to communicate ideas and feelings, imagination, and the establishment of relationships with others. It generally has life-long effects on how children learn to be social beings, to take care of themselves, and to participate in the community. Autism is a developmental disorder of neurobiological origin that is defined on the basis of behavioral and developmental features. Although precise neurobiological mechanisms have not yet been established, it is clear that autism reflects the operation of factors in the developing brain. As yet, known direct links between pathophysiology and behavior in autism are still rare and have not yet had great influence on treatments or diagnoses (see Rumsey et al., 2000). Nevertheless, current biologic research, such as in genetics, may already have important implications for families of children with autistic spectrum disorders.
Autism is best characterized as a spectrum of disorders that vary in severity of symptoms, age of onset, and associations with other disorders (e.g., mental retardation, specific language delay, epilepsy). The manifestations of autism vary considerably across children and within an individual child over time. There is no single behavior that is always typical of autism and no behavior that would automatically exclude an individual child from a diagnosis of autism, even though there are strong and consistent commonalities, especially in social deficits.
A number of years ago, the concept of pervasive developmental disorder (PDD) was introduced to provide an umbrella term for autism and other disorders that include similar impairments in basic social skills but vary in severity or the presence of communication delay and repetitive behaviors. Because of the continuity across autistic disorders, this report addresses both the more narrowly defined disorder of autism and the broader range of autistic spectrum disorder including pervasive developmental disorder—not otherwise specified (PDD-NOS), Asperger’s disorder, and childhood disintegrative disorder. Autistic spectrum disorders are unique in their pattern of deficits and areas of relative strengths. Because of the special characteristics of Rett’s syndrome (i.e., its onset and pattern of deficits), it is not specifically considered in this report. Children with Rett’s syndrome, however, may require similar services to children with autism in some circumstances.
THE CHALLENGE OF EDUCATING CHILDREN WITH AUTISM
Education, both directly of children, and of parents and teachers, is currently the primary form of treatment in autism. For the purposes of this report, education is defined as the fostering of acquisition of skills or knowledge—including not only academic learning, but also socialization, adaptive skills, language and communication, and reduction of behavior problems—to assist a child to develop independence and personal responsibility. Education includes services that foster acquisition of skills and knowledge, offered by public and private schools; infant, toddler, preschool and early education programs; and other public and private service providers. Young children are defined here as children 8 years or younger. Because children with autism are at high risk for other impairments, educational planning must address both the needs typically associated with autistic spectrum disorders and needs associated with accompanying disabilities.
Education of children with autism was accepted as a public responsibility as part of the Education Act of All Handicapped Children in 1975. Yet today, 25 years later, despite the federal mandate for appropriate education and intervention services, the goals, methods, and resources available vary considerably from state to state and from school system to school system. In the last few years, courts have become increasingly active forces in determining the methods applied and the resources allocated by school systems for the education of children with autistic spectrum disorders.
Although there is a very substantial body of research on the treatment and education of these children (Rumsey et al., 2000), this work has not often been clearly integrated into educational decision-making and policy at local or state levels. For example, many treatment approaches and
demonstration projects have disseminated information, yet most have not yet provided appropriate, scientifically rigorous documentation of effectiveness and efficiency. While research in developmental psychology, child psychiatry, and pediatric neurology has become increasingly well integrated, there is a need for more effective communication between professionals in these disciplines and the educators and other professionals who carry out the bulk of treatment and intervention-oriented research.
THE COMMITTEE’S WORK
At the request of the U.S. Department of Education’s Office of Special Education Programs, the National Research Council formed the Committee on Educational Interventions for Children with Autism and charged the committee to integrate the scientific, theoretical, and policy literature and create a framework for evaluating the scientific evidence concerning the effects and features of educational interventions for young children with autism. The primary focus of the charge was early intervention, preschool, and school programs designed for children with autism from birth to age 8. The charge included specific suggestions to examine several issues pertaining to education of children with autism: early intervention, diagnosis and classification, the rights of children with autism under IDEA, mainstreaming, and assistive technology.
To carry out its charge, the committee examined the scientific literature; commissioned papers addressing science and policy issues; examined solicited reports provided by leaders of model intervention programs; and conducted two workshops at which researchers, educators, administrators, practitioners, advocates of individuals with autism, and other interested participants presented to the committee information and perspectives on approaches to address the educational needs of children with autism. The committee also solicited and reviewed written statements, provided by individuals and organizations, summarizing their perceptions of the educational needs of young children with autism. The committee also addressed a specific charge to survey the developing field of assistive technology for young children with autism. Thus, the committee’s activities served as a forum for interdisciplinary discussion of theory and scientific research concerning the evaluation of educational needs of, and methods used with, young children with autism.
The committee conceptualized its task as the integration and evaluation of existing information from multiple sources in order to provide recommendations regarding educational policies affecting families with young children with autism. These policies are carried out in school
systems and state and federal programs. The committee applied strict standards to assess the quality of the large body of information that it assembled. The committee considered arguments of legal rights and documentation of public policy, and current practices in well-established programs, as well as empirical data concerning the effectiveness of various techniques. Within its evaluation of the current scientific literature, the committee’s goal has been to interpret findings as broadly as possible in terms of their implications for early educational practices, while retaining scientific integrity and perspective in considering the strengths and limitations of various bodies of work.
Committee’s Process for Evaluating Evidence
Science is a systematic way of gathering, analyzing, and assessing information. One of the strengths of the field of autism is the many disciplines and areas of scientific inquiry within which it has been addressed. The committee’s approach was to gather information from as wide a range of sources as possible, to assess the strengths and limitations of different sources of information, and to assess the results with an eye toward convergence, particularly from independent sources, of descriptive data, inferential data, and theory.
For example, within the field of autism, there are many approaches to intervention that are widely disseminated but little researched. Some approaches have been greeted with great enthusiasm initially, but have relatively quickly faded out of general use, in part because of their failure to demonstrate worthwhile effects. Other approaches have withstood the test of time across sites and the children and families they serve, though they continue to be largely supported by clinical descriptions of effectiveness, rather than by formal evaluations. Yet wide use and respect cannot be interpreted as clear evidence of effectiveness; therefore, the committee elected to consider information about these approaches in light of more empirically oriented studies.
To achieve a systematic and rigorous assessment of research studies, the committee established guidelines for evaluating areas of strength, limitations, and the overall quality of the evidence; these guidelines are presented in Box 1–1. They are based on approaches used by scientific societies and in recent publications, including: the American Academy of Neurology (Filipek et al., 2000); the American Psychological Association (American Psychological Association, 2000; Barlow, 1996; Chambless and Hollon, 1998); the Society for Clinical Child Psychology (Lonigan et al., 1998); and the New York State Department of Health (1999). A number of comprehensive reviews concerning early intervention in autism also provided examples of ways to systematize information (Dawson and Osterling, 1997; Howlin, 1998; Rogers, 1998; Rumsey et al., 2000). These
BOX 1–1 Guidelines Used to Evaluate Studies
Every research report considered by the committee was assigned to one category (I–IV) for each area (A, B, and C).
guidelines were used by both committee members and commissioned paper authors in their reviews of the literature. Figures 1–1, 1–2, and 1–3 present summarized data from journal articles cited within the areas addressed during the workshops (communication, social development, problem behaviors, intervention methods, and sensorimotor develop-
ment), in terms of percentages of studies falling into different levels of rigor with respect to internal validity, external validity, and generalization. This information is discussed in more detail in Chapter 15 and in the chapters describing those content areas. (For details on the coding of individual studies, see the appendices of the papers cited in the figures.)
One of the difficulties in interpreting research, particularly longitudinal studies, is that standards for scientific research within different theoretical perspectives have changed enormously in the last 20 years, and they continue to evolve. Twenty years ago, behavioral researchers were not as concerned with rigorously standardizing measures or diagnoses, maintaining independence between intervention and assessment, or analyzing the effects of development. Similarly, group designs based on a clinical trials model were not expected to monitor treatment fidelity, equate participants for intellectual or language level, address generalization or maintenance of effects, or justify measures by their clinical value. Therefore, particularly when depicting outcomes from longitudinal studies, reviewers of the literature often have to piece together information
fragmented across studies. Today, that information would have been an expected component of a research design from the start.
Clinical research always involves compromises based on such factors as access to populations and acknowledgment of clinical needs; often, expense is also considered. Even today, there are very different standards across journals and across research communities as to what are considered unacceptable compromises and what is deemed a necessary part of dealing with complex questions. One of the goals that arose from this review was to identify ways of bridging gaps between perspectives in setting guidelines for research about autism. The committee recognized that a range of emphases and designs is important for different questions. Because of the varied nature of the research, the guidelines presented in Box 1–1 were used to characterize the research reviewed. In this way, the strengths and limitations of individual studies could be considered when deriving conclusions based on the consistencies and inconsistencies observed across investigations and theories.
Evidence concerning the effectiveness of instructional and comprehensive programs, strategies, and approaches to intervention for young
children with autism was considered. The committee’s strategy in assessing the effectiveness of components of intervention programs and approaches was to consider, along with the findings of individual research papers, the methodological challenges that many clinical studies face in attempting to control for nonspecific factors, selection biases, and the difficulty in measuring meaningful, generalizable outcomes. Some aspects of interventions, particularly short-term, problem-focused treatments, are much more easily researched than longer-term interventions aimed at more multifaceted concerns (American Psychological Association, 2000). The committee summarized results across areas of interest and approaches to intervention, taking these factors into account. The goal was to integrate this information into a coherent picture of appropriate educational interventions for young children within the autism spectrum, and to acknowledge points of convergence and points of controversy to be addressed in future educational research, practice, and policy. There are no strong studies that compare one comprehensive intervention program with another. Because programs are evolving (and better approaches may be developed in the future), the committee chose to focus on discussion of the effective components and features of each program—
identified on the basis of theory, empirical reports, and consensus across representative programs—rather than to attempt any ranking of specific programs.
There are several related areas the committee hoped to address but, because of limited resources and time, did not. Two issues we did not address are the feasibility and costs of various programs and treatments. Because feasibility and cost-effectiveness formulations involve not only short-term costs to school systems but also short- and long-term costs to health systems and society as a whole, and this information and its analysis are not readily available, it was felt that it would be inappropriate for us to analyze these questions in a superficial way. However, this information is much needed. We were also interested in more directly addressing ways of implementing the changes we recommended, but we were unable within the constraints of this project to acquire sufficient information and expertise about strategies for educational change. Because discrepancies in the kind of programs provided are so great across the United States (Hurth et al., 2000; Mandlawitz, 1999), questions concerning implementation are also crucial.
ORGANIZATION OF THE REPORT
The report is organized according to relationships among issues that, the committee believes, represent the key areas pertaining to educational interventions for young children with autism. Part I addresses the general issue of goals for children with autistic spectrum disorders and their families. Within Part I, Chapter 2 describes how autistic spectrum disorders are diagnosed and assessed and prevalence estimates, Chapter 3 considers the impact on and the role of families, and Chapter 4 discusses appropriate goals for educational services.
Part II presents the characteristics of effective interventions and educational programs. Chapters 5 through 10 discuss fundamental areas of development and behavior that must be addressed by such programs: communication; social, cognitive, sensory and motor development; and adaptive and problem behaviors. Chapter 11 analyzes the characteristics of representative instructional strategies, and Chapter 12 analyzes the features of ten model comprehensive programs and approaches to intervention.
Part III examines the policy and research contexts within which interventions are developed, implemented, and assessed: Chapter 13 presents an overview of public policy and legal issues pertaining to education for children with autism, Chapter 14 addresses the needs for personnel preparation to implement policies, and Chapter 15 identifies the experimental design and methodological issues that should be considered by future researchers in educational interventions for children with autism.