First published Open Access under a Creative Commons license as What is Quantitative Longitudinal Data Analysis this title is now also available as part of the Bloomsbury Research Methods series.Across the social sciences there is widespread agreement that quantitative longitudinal research designs offer analysts powerful scientific data resources. But to date many texts on analysing longitudinal social analysis surveys have been written from a statistical rather than a social science data analysis perspective and they lack adequate coverage of common practical challenges associated with social science data analyses. This book provides a practical and uptodate introduction to influential approaches to quantitative longitudinal data analysis in the social sciences. The book introduces definitions and terms explains the relative attractions of such a longitudinal design and offers an introduction to the main techniques of analysis explaining their requirements statistical properties and their substantive contribution.