 At the start of this entry I listed “value” as a major characteristic of big data and pointed to the crucial role of valuing procedures in identifying, processing, modelling and interpreting data as evidence. Identifying and negotiating different forms of data value is an unavoidable part of big data analysis, since these valuation practices determine which data is made available to whom, under which conditions and for which purposes. What researchers choose to consider as reliable data (and data sources) is closely intertwined not only with their research goals and interpretive methods, but also with their approach to data production, packaging, storage and sharing. Thus, researchers need to consider what value their data may have for future research by themselves and others, and how to enhance that value—such as through decisions around which data to make public, how, when and in which format; or, whenever dealing with data already in the public domain (such as personal data on social media), decisions around whether the data should be shared and used at all, and how.