Part I: Assessment and Diagnosis. Wetherby, Understanding and Measuring Social Communication in Children with Autism Spectrum Disorders. Lord, Richler, Early Diagnosis of Children with Autism Spectrum Disorders. Part II: Screening and Surveillance. Charman, Baron-Cohen, Screening for Autism Spectrum Disorders in Populations: Progress, Challenges, and Questions for Future Research and Practice. Zwaigenbaum, Stone, Early Screening for Autism Spectrum Disorders in Clinical Practice Settings. Part III: Evidence-based Interventions. Yoder, McDuffie, Treatment of Responding To and Initiating Joint Attention. Rogers, Evidence-based Interventions for Language Development in Young Children with Autism. Wolfberg, Schuler, Promoting Social Reciprocity and Symbolic Representation in Children with Autism Spectrum Disorders: Designing Quality Peer Play Interventions. Nadel, Aouka, Imitation: Some Cues for Intervention Approaches in Autism Spectrum Disorders. Howlin, Augmentative and Alternative Communication Systems for Children with Autism. Part IV: Developmental and Neurobiological Issues. Walden, Hurley, A Developmental Approach to Understanding Atypical Development. Mundy, Thorp, The Neural Basis of Early Joint Attention Behavior.