1. George M. Anderson, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Karla K. Ausderau, PhD
2. Kinesiology Department
3. University of Wisconsin–Madison
4. Madison, Wisconsin

1. Grace T. Baranek, PhD, OTR/L, FAOTA
2. Department of Allied Health Sciences
3. University of North Carolina at Chapel Hill
4. Chapel Hill, North Carolina

1. Erin E. Barton, PhD, BCBA-D
2. School of Education and Human Development
3. University of Colorado, Denver

1. Nirit Bauminger-Zviely, PhD
2. School of Education
3. Bar-Ilan University
4. Ramat-Gan, Israel

1. Scott Bellini, PhD
2. Social Skills Research Clinic
3. School Psychology Program
4. Indiana University
5. Bloomington, Indiana

1. Raphael A. Bernier, PhD
2. Center on Human Development and Disability
3. University of Washington
4. Seattle, Washington

1. Stefanie Bodison, OTD, OTR/L, C/NDT
2. Division of Occupational Science and Occupational Therapy
3. University of Southern California
4. Los Angeles, California

1. Leah Langford Booth, MS, CCC-SLP
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Kristen Bottema-Beutel, PhD
2. Department of Special Education
3. Vanderbilt University
4. Nashville, Tennessee

1. Brian A. Boyd, PhD
2. University of North Carolina at Chapel Hill
3. Chapel Hill, North Carolina

1. Jane Thierfeld Brown, EdD
2. University of Connecticut
3. School of Law
4. Hartford, Connecticut

1. Ariane Buescher, MSc
2. Personal Social Service Research Unit
3. London School of Economics and Political Science
4. London, United Kingdom

1. Alice S. Carter, PhD
2. Department of Psychology
3. University of Massachusetts, Boston
4. Boston, Massachusetts

1. Manuel F. Casanova, MD
2. Department of Psychiatry
3. University of Louisville
4. Louisville, Kentucky

1. Ya-Chih Chang, PhD
2. Center for Autism Research and Treatment
3. University of California
4. Los Angeles, California

1. Katarzyna Chawarska, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Frank Cicero, PhD, BCBA
2. Eden II Programs
3. Staten Island, New York

1. Elaine E. Coonrod, PhD
2. TEACCH Autism Program
3. University of North Carolina at Chapel Hill
4. Chapel Hill, North Carolina

1. Christina Corsello, PhD
2. Autism Discovery Institute
3. San Diego, California

1. Naomi Ornstein Davis, PhD
2. Department of Psychiatry
3. Duke University Medical Center
4. Durham, North Carolina

1. Whitney J. Detar, PhD
2. Graduate School of Education
3. University of California, Santa Barbara
4. Goleta, California

1. Oana de Vinck-Baroody, DO
2. Developmental-Behavioral Pediatrics
3. Yale School of Medicine
4. New Haven, Connecticut

1. Peter Doehring, PhD
2. ASD Roadmap
3. Chadds Ford, Pennsylvania

1. Shaunessy M. Egan, MS Ed, BCBA
2. Center for Children with Special Needs
3. Glastonbury, Connecticut

1. Ruth Blennerhassett Eren, EdD
2. Professor of Special Education
3. Southern Connecticut State University
4. New Haven, Connecticut

1. Donia Fahim, PhD, Cert. MRCSLT
2. Hunter College
3. City University of New York
4. New York, New York

1. Kate E. Fiske, PhD, BCBA-D
2. Douglass Developmental Disabilities Center
3. Rutgers, The State University of New Jersey
4. New Brunswick, New Jersey

1. Eric Fombonne, MD
2. Department of Psychiatry
3. McGill University
4. Montreal, Quebec, Canada

1. Solandy Forte, MSW, BCBA
2. Center for Children with Special Needs
3. Glastonbury, Connecticut

1. Megan Freeth
2. Psychology Department
3. University of Sheffield
4. Western Bank, Sheffield, United Kingdom

1. Lauren Gardner, PhD
2. Boling Center for Developmental Disabilities
3. University of Tennessee Health Science Center
4. Memphis, Tennessee

1. Peter F. Gerhardt, EdD
2. Organization for Autism Research
3. Arlington, Virginia

1. Mark P. Groskreutz, PhD
2. Southern Connecticut State University
3. New Haven, Connecticut

1. Rebecca Grzadzinski
2. Teachers College
3. Columbia University
4. New York, New York

1. Abha R. Gupta, MD
2. Department of Pediatrics
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Laura J. Hall, PhD
2. Department of Special Education
3. San Diego State University
4. San Diego, California

1. Antonia Hamilton, PhD
2. School of Psychology
3. University of Nottingham
4. Nottingham, United Kingdom

1. Jan S. Handleman (deceased)

1. Sandra L. Harris, PhD
2. Douglass Developmental Disabilities Center
3. Rutgers, The State University of New Jersey
4. New Brunswick, New Jersey

1. Irva Hertz-Picciotto, PhD
2. Division of Environmental and Occupational Health
3. and
4. MIND Institute
5. UC Davis Medical Center
6. University of California, Davis
7. Davis, California

1. Alison Presmanes Hill, MS, PhD
2. Department of Pediatrics
3. Oregon Health & Sciences University
4. Beaverton, Oregon

1. R. Peter Hobson, MD
2. Institute of Child Health
3. University College London
4. London, United Kingdom

1. Patricia Howlin, MSc, PhD
2. St. George's Hospital Medical School
3. University of London
4. London, United Kingdom

1. Kara A. Hume, PhD
2. FPG Child Development Institute
3. University of North Carolina at Chapel Hill
4. Carrboro, North Carolina

1. Lisa V. Ibañez
2. University of Washington Autism Center
3. Seattle, Washingon

1. Brooke Ingersoll, PhD
2. Department of Psychology
3. Michigan State University
4. East Lansing, Michigan

1. William R. Jenson, PhD
2. Department of Educational Psychology
3. University of Utah
4. Salt Lake City, Utah

1. Connie Kasari, PhD
2. Center for Autism Research and Treatment
3. University of California at Los Angeles
4. Los Angeles, California

1. So Hyun Kim, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Martin Knapp
2. London School of Economics and Political Science
3. King's College London
4. London, United Kingdom

1. Lynn Kern Koegel, PhD
2. Koegel Autism Center
3. University of California, Santa Barbara
4. Goleta, California

1. Robert L. Koegel, PhD
2. Koegel Autism Center
3. University of California, Santa Barbara
4. Goleta, California

1. Elizabeth Lanter, PhD, CCC-SLP
2. Department of Communication Sciences and Disorders
3. Radford University
4. Radford, Virginia

1. Jennifer Leung, MD
2. Department of Pediatrics
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Lauren M. Little, PhD
2. Department of Allied Health Sciences
3. University of North Carolina at Chapel Hill
4. Chapel Hill, North Carolina

1. James W. Loomis, PhD
2. Center for Children with Special Needs
3. Glastonbury, Connecticut

1. Catherine Lord, PhD
2. Center for Autism and the Developing Brain
3. Weill Cornell Medical College
4. White Plains, New York

1. Kristen Lyall, ScD
2. MIND Institute
3. UC Davis Medical Center
4. University of California, Davis
5. Davis, California

1. Megan C. Lyons, MS, CCC-SLP
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Suzanne L. Macari, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. David S. Mandell, ScD
2. University of Pennsylvania School of Medicine
3. Philadelphia, Pennsylvania

1. Kimberly Markoff, MSEd
2. St. John's Pavilion
3. Springfield, Illinois

1. Andrés Martin, MD, MPH
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Megan P. Martins, PhD, BCBA-D
2. Center for Development & Disability
3. University of New Mexico Health Sciences Center
4. Albuquerque, New Mexico

1. Gary S. Mayerson, JD
2. Mayerson & Associates
3. New York, New York

1. Erik Mayville, PhD, BCBA-D
2. Institute for Educational Planning
3. Connecticut Center for Child Development
4. Milford, Connecticut

1. Carla A. Mazefsky, PhD
2. Department of Psychiatry
3. University of Pittsburgh
4. Pittsburgh, Pennsylvania

1. Iain McClure, MB, BS
2. University of Edinburgh
3. Edinburgh, United Kingdom

1. James C. McPartland, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Judith Meyers, PhD
2. The Child Health and Development Institute of Connecticut, Inc.
3. Farmington, Connecticut

1. Amber R. Miller, BA
2. Graduate School of Education
3. University of California, Santa Barbara
4. Goleta, California

1. Elizabeth Milne
2. Psychology Department
3. University of Sheffield
4. Sheffield, United Kingdom

1. Pat Mirenda, PhD
2. Centre for Interdisciplinary Research and Collaboration in Autism
3. The University of British Columbia
4. Vancouver, British Columbia

1. Stewart Mostofsky
2. Laboratory for Neurocognitive and Imaging Research
3. Kennedy Krieger Institute
4. Baltimore, Maryland

1. Elizabeth C. Nulty, MS, BCBA
2. Center for Children with Special Needs
3. Glastonbury, Connecticut

1. Leona Oakes, BA
2. Strong Center for Developmental Disabilities
3. University of Rochester Medical Center
4. Rochester, New York

1. Samuel L. Odom, PhD
2. Frank Porter Graham Child Development Institute
3. University of North Carolina
4. Chapel Hill, North Carolina

1. Robert E. O'Neill
2. Department of Special Education
3. University of Utah
4. Salt Lake City, Utah

1. Mark J. Palmieri, PsyD, BCBA-D
2. School Consultation Services
3. Center for Children with Special Needs
4. Glastonbury, Connecticut

1. L. Diane Parham, PhD
2. Occupational Therapy Graduate Program
3. University of New Mexico
4. Albuquerque, New Mexico

1. Rhea Paul, PhD, CCC-SLP
2. Department of Speech-Language Pathology
3. Sacred Heart University
4. Fairfield, Connecticut

1. Kevin A. Pelphrey, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Lauren Pepa, BA
2. Douglass Developmental Disabilities Center
3. Rutgers, The State University of New Jersey
4. New Brunswick, New Jersey

1. Marie-Christine Potvin, PhD, OTR, ATP
2. Center on Disability and Community Inclusion
3. University of Vermont
4. Burlington, Vermont

1. Kelly Powell, MA
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Michael D. Powers, PsyD
2. Center for Children with Special Needs
3. Glastonbury, Connecticut
4. and
5. Child Study Center
6. Yale University School of Medicine
7. New Haven, Connecticut

1. Patricia A. Prelock, PhD
2. College of Nursing and Health Sciences
3. University of Vermont
4. Burlington, Vermont

1. Keith C. Radley, III, PhD
2. Department of Psychology
3. University of Southern Mississippi
4. Hattiesburg, Mississippi

1. Rajani Ramachandran, PhD
2. University of Calicut
3. Kerala, India

1. Brian Reichow, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Sally J. Rogers, PhD
2. UC Davis Medical Center
3. University of California, Davis
4. and
5. MIND Institute
6. Sacramento, California

1. Jessica L. Rohrer, MS, BCBA
2. Center for Children with Special Needs
3. Glastonbury, Connecticut

1. Justin Rowberry, Major, USAF
2. Developmental and Behavioral Pediatrics
3. Mike O'Callaghan Federal Medical Center
4. Nellis AFB, Nevada

1. Michael Rutter, CBE, MD, FRCP, FRCPsych, FRS
2. Social, Genetic and Developmental Psychiatry Centre
3. Institute of Psychiatry
4. King's College, London
5. London, United Kingdom

1. Maura G. Sabatos-DeVito, MS
2. Department of Psychology, Developmental Program
3. University of North Carolina at Chapel Hill
4. Chapel Hill, North Carolina

1. Micheal P. Sandbank, MEd
2. Department of Special Education
3. Vanderbilt University
4. Nashville, Tennessee

1. Liliane Beaudoin Savard, PT, DPT, PCS, PLLC
2. Zippy Life Physical Therapy
3. Montpelier, Vermont

1. Lawrence Scahill, MSN, PhD
2. School of Nursing
3. and
4. Child Study Center
5. Yale University School of Medicine
6. New Haven, Connecticut

1. Rebecca J. Schmidt, PhD, MS
2. Department of Public Health Sciences
3. MIND Institute
4. UC Davis Medical Center
5. University of California, Davis
6. Davis, California

1. Elizabeth Schoen Simmons, MS, CCC-SLP
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Katelyn Selver, BA
2. Strong Center for Developmental Disabilities
3. Department of Pediatrics
4. University of Rochester Medical Center
5. Rochester, New York

1. Elizabeth Sheppard, PhD
2. Psychology Department
3. University of Nottingham Malaysia Campus
4. Selangot Darul Ehsan, Malaysia

1. Frederick Shic, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Tristram Smith, PhD
2. Strong Center for Developmental Disabilities
3. Department of Pediatrics
4. University of Rochester Medical Center
5. Rochester, New York

1. Laurie Snider, PhD, OTR(C)
2. School of Physical and Occupational Therapy
3. McGill University
4. Montreal, Canada

1. Wendy L. Stone, PhD
2. UW Autism Center
3. University of Washington
4. Seattle, Washington

1. Helen Tager-Flusberg, PhD
2. Department of Anatomy and Neurobiology
3. Boston University School of Medicine
4. Boston, Massachusetts

1. Anita Thapar, MBBCh, PhD, FRCPsych, FMedSci
2. MRC Centre for Neuropsychiatric Genetics and Genomics
3. and
4. Institute of Psychological Medicine and Clinical Neurosciences
5. Cardiff University School of Medicine
6. Cardiff, Wales, United Kingdom

1. Caitlin S. Tillberg
2. Frank H. Netter School of Medicine
3. Quinnipiac University
4. North Haven, Connecticut

1. Rachael M. Tillman, BA
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Katherine D. Tsatsanis, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Nita Vaswani, DO
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Laurie Vismara, PhD
2. Psychiatry and Behavioral Sciences
3. University of California, Davis
4. and
5. MIND Institute
6. Sacramento, California

1. Giacomo Vivanti, PhD
2. Department of Psychology
3. Olga Tennisson Autism Research Centre
4. La Trobe University
5. Melbourne, Australia

1. Fred R. Volkmar, MD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Allison Wainer, MA
2. Department of Psychology
3. Michigan State University
4. East Lansing, Michigan

1. Christine Wenzel, BA, MA
2. Center for Students with Disabilities
3. University of Connecticut
4. Storrs, Connecticut

1. Alexander Westphal, MD
2. Department of Psychiatry
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Susan W. White, PhD
2. Virginia Tech Autism Center
3. Virginia Tech
4. Blacksburg, Virginia

1. Lisa A. Wiesner, MD
2. Pediatrics and Adolescent Medicine
3. Orange, Connecticut

1. Tiffany Woynaroski, MS, SLP
2. Vanderbilt Kennedy Center
3. Nashville, Tennessee

1. Daniel Y.-J. Yang, PhD
2. Child Study Center
3. Yale University School of Medicine
4. New Haven, Connecticut

1. Paul Yoder, PhD
2. Vanderbilt Kennedy Center
3. Nashville, Tennessee

1. Katharine E. Zuckerman, MD, MPH
2. Division of General Pediatrics and Child and Adolescent Health Measurement Initiative
3. Oregon Health and Sciences University
4. Portland, Oregon

The assessment of individuals with autism spectrum disorder (ASD) calls on the expertise of a variety of disciplines, including pediatrics, neurology, psychiatry, psychology, special education, speech-language pathology, and physical rehabilitation, to name a few. In this section, we ask expert clinicians from these disciplines to discuss the assessment process from their point of view. Our authors address:

• Major goals of assessment, including:
  • screening to determine the need for further assessment;
  • diagnostic evaluation that establishes eligibility for services;
  • differential diagnosis that distinguishes ASD from other neuropsychiatric syndromes;
  • identifying baseline function in a range of developmental areas, against which progress in intervention can be measured;
  • characterization of strengths and needs of the individual, in order to guide the development of intervention objectives and procedures; and
  • detailed description of functioning across a range of developmental areas, in order to characterize the range of phenotypic expression within the syndrome.
• Methods available for rigorous assessment of core symptoms associated with ASD, including:
  • standardized instruments,
  • observational protocols,
  • criterion-referenced probes, and
  • caretaker and teacher questionnaires and interviews.
• The application of evidence-based practice to assessment.

These issues not only impact clinical practice in ASD, but also affect the conduct of research. Until recently, there have been few well-standardized, validated, and reliable measures that provide diagnostic and assessment information about individuals with ASD, making both creditable diagnoses and replicable research problematic. In the area of screening and diagnostic assessment, great strides have been made since the previous edition of this handbook in the development and validation of measures designed specifically to determine the need for assessment as well as the diagnosis of ASD. This progress has come as a result of intensive research efforts to assess the sensitivity, specificity, and validity of screening and diagnostic measures. Still, issues and controversies remain regarding the construction, implementation, and interpretation of these measures, many of which are discussed in the chapters in this section.

Differential diagnosis within the autism spectrum and among ASD and other disorders remains stubbornly difficult, particularly for the youngest children, for whom early identification is so crucial to optimal outcomes. Recent changes in DSM-5 highlight this issue, and heated debate continues about the propriety of moving from older systems identifying subgroups within the autism spectrum to a system of treating it as an undifferentiated continuum. As chapters in this section demonstrate, assessment contributes to this debate by providing the opportunity to answer questions on the basis of data rather than theory or anecdotal experience. An important goal of assessment is to move beyond global descriptions to more fine-grained, precise documentation of functioning across domains, including cognitive, linguistic, communicative, social, motor, and adaptive behaviors. These fine-grained descriptions of individual patterns of behavior and ability contribute in important ways to the identification of an individual's baseline function for gauging progress in intervention and of the profile of strengths and needs that guide the development of educational goals. In addition, though, they provide the opportunity to explore patterns across individuals. The discovery of consistent patterns of behavioral and cognitive functions provides an empirical basis for testing hypotheses about the existence and validity of subgroups within the broad autism spectrum, and the possibility of finding biological correlates, including those at genetic, neuroanatomical, neurophysiological, or neurochemical levels. The identification of subgroups with such biomarkers holds out the promise that specific medical or pharmacological interventions may one day be devised to address specific elements of the syndrome within specific subgroups. The fulfillment of this promise depends to a great degree on the precision of assessment information collected, and on the accumulation of this information in research based in psychometrically sound clinical instruments and structured observation.

An additional message that emerges from this section is the importance of seeing ASD within a developmental framework. Despite the unique symptoms and uneven skills often seen in individuals with ASD, many strands of their development nonetheless follow the normative sequence. This normative aspect of development is a crucial consideration in determining the needs of individuals with ASD, in terms of focusing on developmentally appropriate social, academic, self-help, and motor skills. It is incumbent upon clinicians not to be diverted by the many atypical behaviors of people with ASD into ignoring the aspects of their function that will allow them to take advantage of interactions with peers and other members of their community. Detailed assessment information collected within a developmental framework, including well-constructed instruments designed specifically for individuals with ASD as well as psychometrically sound instruments that take a broader developmental spectrum into account, is essential for optimizing these opportunities. Many chapters in this section provide guidelines and methods for achieving these developmentally situated evaluations.

Another point made clear in this section is the degree of experience, expertise, and teamwork needed to accomplish the kind of multidimensional assessment that will both deeply characterize an individual's diagnostic and developmental status and provide the fine-grained data that will inform and advance research on ASD. Individuals with ASD can show unusual preferences for reinforcement, attentional, and motivational characteristics, and uneven profiles across domains. These differences can make it challenging for them to participate in assessment activities, and to demonstrate their optimal level of competence. Clinicians performing assessments need more than knowledge of their instruments; they need understanding of the particular challenges individuals with ASD face in the assessment process, insight and empathy with their struggles, and patience and flexibility to elicit the best performance. They need, too, to work closely with colleagues from other disciplines and to think creatively about planning the overall assessment experience to maximize the client's opportunities for success. No one discipline has a monopoly on the diagnostic process, and the most thorough and effective assessments will involve interprofessional collaboration in planning, administering, and interpreting assessment data.

Finally, the results of assessments must be placed within the context of the opportunities the individual has had for social relations, academic achievement, recreation, and self-advocacy. We can anticipate that children who had consistent, intensive educational programming since early childhood will appear quite different on assessment than those with more restricted experiences. Moreover, contextually based assessments can help to locate ways in which the environment can be engineered to enhance appropriate experiences that will enable the acquisition of a range of academic and practical skills. Chapters in this section provide examples of the ways in which this kind of ecological assessment can round out the picture of the skills and needs of individuals with ASD.

The results of careful and comprehensive assessment are a function of the individual's congenital biological endowment, maturation, personal experiences, and community opportunities. Used appropriately, objective, rigorous assessment provides both the best guide to comprehensive, effective intervention and the most direct path to advancing research on this complex syndrome.