Abstract Knowledge, as a non-natural construction, may be based on our ability to hack the data coming from the world. Two questions now become pressing. The first, addressed in this chapter, concerns the quality of the information we are able to generate, when we are dealing with truthful contents. The second question concerns the truthfulness of such contents and is the subject of Chapter 6. This chapter generalizes the analysis and applies it to a popular topic, that of big data. It is argued that the real epistemological challenge posed by the zettabyte era is small patterns. The chapter focuses on information quality (IQ). Which data may be useful and relevant, and so worth collecting, curating, and querying, in order to exploit their valuable (small) patterns? The chapter argues that the standard way of seeing IQ in terms of being fit-for-purpose is correct but needs to be complemented by the methodology of abstraction introduced in Chapter 2, which allows IQ to be indexed to different purposes.