Web Science is an interdisciplinary field. Motivated by the unforeseen scale and impact of the web, it addresses web-related research questions in a holistic manner, incorporating epistemologies from a broad set of disciplines. There has been ongoing discussion about which disciplines are more or less present in the community, and about defining Web Science itself: there is, however, a dearth of empirical work in this area.This paper presents an analysis of the presence of different disciplines in Web Science. We applied Natural Language Processing and topic extraction to a corpus of Web Science material, analysing it with graphing and visualisation tools, MatLab and an expert survey. We discovered four communities within Web Science, and trends in the conference series over time (a strong impact from collocation) and format (posters covering a broader range of topics than papers). The expert survey linked highly ranked terms with disciplines, yielding strong links with Communication, Computer Science, Psychology, and Sociology. Controversially, experts described highly ranked topics and suggested disciplines (extracted from WebSci CFPs) as not reflecting the nature of Web Science.