Part I. Conceptual issues -- Chapter 1. Epistemology of Complexity (Alberto Peruzzi) -- Chapter 2. Building Knowledge. Between Measure and Meaning: A Phenomenological Approach (Rocco Sacconaghi) -- Part 2. Methodological Issues -- Chapter 3. Socio-Economic Statistics for A Complex World: Perspectives and Challenges in the Big Data Era (Marco Fattore) -- Chapter 4. Developing Indicators and Managing the Complexity (Filomena Maggino) -- Chapter 5 -- Dealing with Syntheses in a System of Indicators (Filomena Maggino) -- Chapter 6. Scalability of Composite Indices: Complexity Complications (Kenneth C. Land, Vicki L. Lamb, Xiaolu Zang) -- Part 3. Technical Issues -- Chapter 7. Synthesis of Indicators: The Composite Indicators Approach (Matteo Mazziotta & Adriano Pareto) -- Chapter 8. Synthesis of Indicators: The Non-Aggregative Approach (Marco Fattore) -- Chapter 9. The Role of Extended IRT Models for Composite Indicators Construction (Michela Gnaldi, Simone Del Sarto & Filomena Maggino) -- Part 4. Particular Experiences -- Chapter 10. Synthesis of Indicators Through Weighting: The Experiences of Quality of Life Measures (Chang-Ming Hsieh) -- Chapter 11. The Role of Normalization in Building Composite Cndicators. Rationale and Consequences of Different Strategies (Ludovico Carrino) -- Chapter 12. Steps Towards a Synthetic Measure Derived from a Partially Ordered Set (Giovanna Boccuzzo & Giulio Caperna) -- Chapter 13. Joint analysis of Structural Models and Performance: Merging Clustering and Composite Indicators in the Analysis of Europe 2020 strategy (Tommaso Rondinella & Elena Grimaccia).This volume discusses the many recent significant developments, and identifies important problems, in the field of social indicators. In the last ten years the methodology of multivariate analysis and synthetic indicators construction significantly developed. In particular, starting from the classical theory of composite indicators many interesting approaches have been developed to overcome the weaknesses of composites. This volume focuses on these recent developments in synthesizing indicators, and more generally, in quantifying complex phenomena.