For examining the various groups in various subreddits. /u/RedditAnalysisBot is open source. You can view it here

I filter posts by flair now. Meta posts

Bugged drilldowns

To search for a drilldown, in the searchbar of this subreddit enter:

flair:"SubredditName"

I open sourced the bot because: If there's a flaw it's more likely to be noticed

It offers some transparency

If I disappear and someone wants to run more drilldowns they'll be able to without building another bot from scratch

How does the bot work? Updated 2014-09-05 First, it grabs the latest 1000 threads from a subreddit's hot queue.

Second, it compiles a list of usernames from the creators of those threads along with the people commenting in them (while ignoring submissions/comments with a karma score of -4 and lower).

Then, the bot crawls through their last 1000 comments/submissions in their user history to find out where else they post (also ignoring comments/submissions with a karma score of -4 or lower) while keeping tally to see which subreddits have the highest overlap.

Finally, the bot calculates the similarity between subreddit samples.

How to calculate similarity between two subreddits: sqrt(AB * BA) / sqrt(A * B) AB = overlapping users from subreddit A BA = overlapping users from subreddit B A = number of users found by the bot in subreddit A B = number of users found by the bot in subreddit B

Other stuff: I excluded default and former default subreddits

I take requests for specific subreddits.