Necessary Condition Analysis (NCA) is a new research method for data analysis. Its unique feature is the use of 'necessary but not sufficient' logic to detect the critical 'must have' factors in datasets, rather than average effects. This book introduces this methodology at an advanced level, taking readers through the theoretical underpinning and its varied application in empirical research across the social sciences and beyond. Aimed at PhD students and researchers, data analysts, practitioners, and others, the book helps readers develop a deeper understanding of the NCA approach and apply it effectively and with high-quality standards. It brings together the fundamentals of NCA and integrates the most recent methodological advancements and tools. No prior knowledge of NCA is required but readers would benefit from familiarity with the basics of research methodology. Key features: • Addresses a new data analysis method. • Provides a deeper understanding of the method. • Includes hands on practical recommendations for application.