This definitive clinical reference comprehensively reviews the most advanced methods for assessing the person in pain. The field's leading authorities present essential information and tools for evaluating psychosocial, behavioral, situational, and medical factors in patients' subjective experience, functional impairment, and response to treatment. Empirically supported instruments and procedures are detailed, including self-report measures, observational techniques, psychophysiological measures, and more. Best-practice recommendations are provided for assessing the most prevalent pain syndromes and for working with children, older adults, and people with communication difficulties. The book also weighs in on the limitations of existing methods and identifies key directions for future research.