Entities of Interest

In the era of big data, we continuously - and at times unknowingly - leave behind digital traces, by browsing, sharing, posting, liking, searching, watching, and listening to online content. When aggregated, these digital traces can provide powerful insights into the behavior, preferences, activities, and traits of people. While many have raised privacy concerns around the use of aggregated digital traces, it has undisputedly brought us many advances, from the search engines that learn from their users and enable our access to unforeseen amounts of data, knowledge, and information, to, e.g., the discovery of previously unknown adverse drug reactions from search engine logs. Whether in online services, journalism, digital forensics, law, or research, we increasingly set out to exploring large amounts of digital traces to discover new information. Consider for instance, the Enron scandal, Hillary Clinton's email controversy, or the Panama papers: cases that revolve around analyzing, searching, investigating, exploring, and turning upside down large amounts of digital traces to gain new insights, knowledge, and information. This discovery task is at its core about "finding evidence of activity in the real world." This dissertation revolves around discovery in digital traces, and sits at the intersection of Information Retrieval, Natural Language Processing, and applied Machine Learning. We propose computational methods that aim to support the exploration and sense-making process of large collections of digital traces. We focus on textual traces, e.g., emails and social media streams, and address two aspects that are central to discovery in digital traces.