This book presents contributions from migration sociologists inspired by Florian Znaniecki's theory and the results of his studies to conduct their own research in countries like Austria, China, Greece and Poland. The authors evaluate today's migration phenomena with reference to a coherent theoretical system. The book can be used as a manual presenting the tools for examining the migration experience from many angles: a sense of national identity (ethnic and civic), family ties, the importance of the social environment in the process of an individual's integration with the society or an evolution of entire social systems within which the migrants operate.