One of the major changes in the social science research landscape in recent years has been the introduction of computerised panel surveys in Europe and the US which make longitudinal data widely available to graduate students for the first time. Elisabetta Ruspini here provides a concise yet comprehensive introduction to the issues involved in this kind of research. Defines the concept of longitudinal research Gives guidance on sources of longitudinal data in Europe and the US and their strengths and weaknesses Discusses the choices that need to be made in this kind of research - for instance the advantages and disadvantages of certain types of research data and of different types of analysis Highlights some of the problems involved, e.g. the issue of comparability within longitudinal research.