So that we can construct queries which take into account whether a user is registered or unregistered, please add the UserType field to Data Explorer.

Currently there is no way to do this, since the field is not exposed:

Where is UserType?

Note that I'm not asking to see the user's employee status; it's probably not a good idea to expose that.

  • 1
    Might just as well add is_employee and is_moderator at the same time? Commented Sep 13, 2013 at 6:12
  • What do you mean by unregistered users? You mean people with no account on the site (those with deleted accounts, and people whose questions were migrated to a site they have no account on), or people who just post like userXXXXXXX type members? Because while the latter may not have officially registered, they still have an account that sticks with them through cookies. What is the merit of distinguishing the two exactly?
    – jmac
    Commented Nov 14, 2013 at 1:59
  • @jmac One could possibly want statistics on how committed registered users are vs. unregistered users. Just one possibility. Commented Nov 14, 2013 at 3:41
  • @jmac Or post quality, which was the example already given (you somehow missed it; the link probably needs a red freehand circle). Commented Nov 14, 2013 at 3:43
  • 4
    Ah, apologies. I did miss the link. Okay, I understand the request now. Bear in mind that this is not going to give clear stats because users can post 'unregistered' initially, and then register later, and be counted as registered posts (even though the original posts were unregistered). I'd guess this will introduce significant bias to the data as I'd wager that better unregistered contributors are more likely to become registered later (to keep their rep), skewing the quality assessment of unregistered. So you may want to add registered date to the account to be able to distinguish
    – jmac
    Commented Nov 14, 2013 at 3:49
  • Yes, this would be very useful! Did this go anywhere further? Commented Jan 14, 2017 at 12:00

1 Answer 1


The only risk in this is exposing cookie-based accounts that have a fair amount of rep associated with them as being possibly abandoned. If the last activity is more than a few months ago, someone's lost their cookie and probably won't realize they're disenfranchised from those contributions for months, years, or possibly ever.

Someone with less than noble intentions could then:

  • Find unregistered accounts from years ago that still have a gravatar hash
  • Use a rainbow table to get the email
  • Request a merge and possibly profit, since they'd basically know the only non-public thing about the account. (Geez, I think I was in an Airport in Belgium when I wrote that answer that got 40 votes, can't remember)
  • Probably uber-rare these days, I have to dig a bit, but still a concern. I've caught what I think is possible attempted abuse of auto-merging; a process which we've made no secret about in the past. That's what peaked my eyebrow.

You can happen upon these now opportunistically, but there's no easy way to query for them. Adding that type gives you this ability.

Beyond that, I have no real misgivings about including it in future dumps (which would basically let you backfill all previous dumps to some extent). What you won't get is any means of knowing if an account we now say is registered was unregistered 3 years ago. If it's unregistered today, it was unregistered at any time in the past (you can't go from registered to unregistered).

There are very interesting use cases here:

  • Moderators looking to examine how different sets of people actually use their sites
  • Researchers interested in many aspects surrounding anonymous participation
  • Researchers working on things like tag prediction (a very common thesis these days) wanting to split the user base even more while looking at what their implementation picked vs. what a user actually went with
  • ... there are uses for this in the dump, let's just leave it at that before I start wandering

I have to think about it a bit and make sure I'm not missing something horrendous that might happen if we included this. If I come up empty, I'll recommend internally that we do it.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .