The emphasis of school psychology on prevention, early intervention, assessment, collaboration, and problem solving requires counselors to have a tremendous range of evidence-based knowledge. This publication, divided into two volumes, is designed to provide a comprehensive reference for school psychologists on contemporary research and perspectives related to quality professional services. The information emphasizes a problem-solving approach to professional practice to improve student performance and enhance educational success in a demonstrable manner. The two volumes are divided into four parts with chapters clustered around the concepts of professional focus, improving student performance, assessment domains and special populations, and appendixes with practical reference materials. The chapters in Part 1 are related to the enhancement of professional services and the topics range from revisiting the shifting paradigm in school psychology to the standard topics on ethics, supervision, and accountability. Part 2 contains topics on interventions to improve student academic and behavioral performance. Part 3 considers assessment domains and special populations. Part 4 provides a set of appendices for reference which include standards, a listing of training programs across the country, and a full listing of National Association of School Psychologists position statements, training standards, and ethics. (Contains 48 tables, 101 figures, 4 appendixes, and over 900 references.) (JDM)