Book excerpt: To analyse social and behavioural phenomena in our digitalized world, it is necessary to understand the main research opportunities and challenges specific to online and digital data. This book presents an overview of the many techniques that are part of the fundamental toolbox of the digital social scientist. Placing online methods within the wider tradition of social research, Giuseppe Veltri discusses the principles and frameworks that underlie each technique of digital research. This practical guide covers methodological issues such as dealing with different types of digital data, construct validity, representativeness and big data sampling. It looks at different forms of unobtrusive data collection methods (such as web scraping and social media mining) as well as obtrusive methods (including qualitative methods, web surveys and experiments). Special extended attention is given to computational approaches to statistical analysis, text mining and network analysis. Digital Social Research will be a welcome resource for students and researchers across the social sciences and humanities carrying out digital research (or interested in the future of social research).