 An alternative is to define big data not by reference to their physical attributes, but rather by virtue of what can and cannot be done with them. In this view, big data is a heterogeneous ensemble of data collected from a variety of different sources, typically (but not always) in digital formats suitable for algorithmic processing, in order to generate new knowledge. For example boyd and Crawford (2012: 663) identify big data with “the capacity to search, aggregate and cross-reference large datasets”, while O’Malley and Soyer (2012) focus on the ability to interrogate and interrelate diverse types of data, with the aim to be able to consult them as a single body of evidence. The examples of transformative “big data research” given above are all easily fitted into this view: it is not the mere fact that lots of data are available that makes a different in those cases, but rather the fact that lots of data can be mobilised from a wide variety of sources (medical records, environmental surveys, weather measurements, consumer behaviour). This account makes sense of other characteristic “v-words” that have been associated with big data, including: