My research is in machine learning with an emphasis on natural language processing. More specifically, I primarily study machine learning scenarios where there is an interaction with a domain expert during the learning procedure (active learning, interactive knowledge acquisition) and scaling these protocols up to real-world applicability. Therefore, I am also interested in the examination of complex output spaces (e.g. structured output, ranking data), exploring methods to exploit interdependencies between learned classifiers (e.g. structured learning), and effectively utilizing unlabeled data whenever possible (e.g. unsupervised learning, domain adaptation).