Chapter 3 describes the fundamental research questions, empirical approaches and findings of language documentation and descriptive linguistics. These are two closely interrelated linguistic subfields concentrating on the collection and/or analysis of primary data for the purposes of documenting and describing languages (corpora and grammars). Methodological issues include considerations on research objects, fieldwork, as well as techniques and procedures of data collection, editing, and analysis such as transcription, annotation, and elicitation. The chapter ends with recommendations for further reading and a list of short exercises and ideas for small research projects.