To find out, we compute metrics of user behavior using the data sample of 1000 users and 10 million posts described in Section 5.2.
we calculate (1) activity: a user's total number of posts, (2) breadth: the number of subreddits a user has posted in, (3) focus: the proportion of a user's posts that appear in the subreddit where they are most active, and (4) engagement: the average number of posts a user contributes to each discussion they engage in.