While the field of ELT studies sees continued horizontal and vertical diversification, it is also time to take stock of what has made the discipline the field it presents itself as today. As horizontal diversification, we can identify trends that involve a continued inclusion of more fields of study into the family of methods and approaches of ELT. Especially in the technical sense, e-learning has matured and new forms of online learning and teaching have emerged, be it via teleconferences or short-message services for vocabulary training. However, a massive extension has occurred within the so-called social media. The vertical dimension affects a depth of analysis not seen even a decade ago, when for example small and relatively simple learner corpora were used for linguistic analysis that rarely went beyond rote frequency counts. The increasing sophistication in these two dimensions is also reflected in the research papers collected in this volume.