With an emphasis on secondary education, this extensive book examines the vital role that assessment plays in enhancing student learning outcomes. It looks at the origins of assessment from both historical and modern angles, dissecting the variations in testing approaches and how best to use them for formative, summative, and ongoing assessment. The book explores how new methods made possible by developments in technology and analysis might change traditional assessment to become more personalized, integrated, and useful for measuring higher-order abilities. Through practice frameworks, policy recommendations, and innovative case studies, it offers crucial insights into creating and putting into place fair assessment systems that uphold equity, transparency, and trust. These systems also inform curriculum design and teaching strategies that are adapted to the changing needs of middle and high school students in the twenty-first century.