Table 4: Number of activities before and after flattening; “+” denotes activates which were created during a given flattening process.

Activity typeNumber of activities before flattening (in HPSN)Number of activities after flattening (in FPSN)
NewFinal objects: topic groupsNewFinal objects: topicsNewFinal objects: posts

Forum creation activity1+692+2336+1,3272
Topic group addition692692+2336+13,272
Topic addition2,3362,3362336+13,272
Topic member subscribing5,7885,7885788793,245
Post authoring13,27213,27213,27213,272
Post commenting49494949