 Big data analysis may therefore constitute the ultimate instance of a distributed cognitive system. Where does this leave accountability questions? Many individuals, groups and institutions end up sharing responsibility for the conceptual interpretation and social outcomes of specific data uses. A key challenge for big data governance is to find mechanisms for allocating responsibilities across this complex network, so that erroneous and unwarranted decisions—as well as outright fraudulent, unethical, abusive, discriminatory or misguided actions—can be singled out, corrected and appropriately sanctioned. Thinking about the complex history, processing and use of data can encourage philosophers to avoid ahistorical, uncontextualized approaches to questions of evidence, and instead consider the methods, skills, technologies and practices involved in handling data—and particularly big data—as crucial to understanding empirical knowledge-making.