Collective Emotions Online and Their Influence on Community Life – Supporting Information File S1

S1 Data structure. The three datasets on which sentiment analysis was performed are characterized by different structures. In the case of Blogs06, all posts were originally arranged in chains of successive comments, as shown in Fig. S1B. In other words new posts are automatically added after the last post. On the other hand, the BBC and Digg data are arranged in a forum-like structure (see Fig. S1A), meaning that each user may make a comment to any previous post, thus starting a separate discussion. However, for the purpose of this study each discussion (thread) in each dataset was arranged chronologically, as in Fig. S1B. In this way it was possible to compare these different communities. Although BBC and Digg have a forum-like structure, the default view presented to the user was chronological. Thus a chronological simplification for analysis can be justified.