This book deals with the measurement of social class, social standing, social status - generally speaking - of social position, considered as placement in the social stratification system. Social scientists ae divided into those who favor categorical approaches to socio-economic calssification and those who prefer continous measures, which assume that differences between elementary units can be captured in one dimension that is represented by a single parameter. We propose here a harmonized socio-occupational classification, referred to as Social Classification of Occupations (SCO), which may be suitable for analyzing sociologically derived class categories in East European countries.