In this dissertation I address what I call the dual nature of web data. I underline how central content objects of online platforms not only hold social and cultural data but also encapsulate programmed actions that afford social activity with these objects (cf. Engestròˆm, 2005). By connecting concepts from object-oriented programming with methodologies for a sociology of associations, I repurpose the unitary actions (cf. Agre, 1994) defined by platforms on natively digital objects to add methods, measures, and research instruments to digital methods (Rogers, 2013a) and controversy mapping (Venturini & Munk, 2021). Addressing calls to attend to mediation effects in platform data (Lazer et al, 2021; Marres, 2015a), my focus on the dual nature of web data highlights both how online platforms participate in social activity and how object-activity can be repurposed to demarcate issue spaces, study the representation of voice, and characterize issues using measures of partisanship and controversiality. Based on data from Twitter, Yahoo! search, and Wikipedia, my case studies contribute to academic fields like journalism studies, political communication, the public understanding of science and technology, and cultural heritage.