Large research networks naturally form complex communities with overlapping but not identical expertise. To map the distribution of professional competence in field of "technology-enhanced learning", the lexical semantics expressed in research articles published in a representative, large-scale conference (ED-MEDIA) can be investigated and changes in the topics covered can be tracked over time. Within this contribution, the two years 2000 and 2008 are used to contrast the change in meaning structure. In both cases, first a quantitative investigation is applied, directly followed by a two-fold qualitative analysis. Results indicate that the field has opened up to new areas, thus diversifying research; at the same time, certain terminology disappears as interests shift and research is finalised for some of the underlying problems. (Contains 2 tables and 10 figures.)