Three-vote close/reopen test - results

Question

Three-vote close and reopen has been something I've been thinking about for ... a really long time. I'm really happy to finally be able to present the results of this test to you all. This post is long, so the short version is - we tested three-vote closure in two ways, and in general, this seems to help sites in both cases. I've tried to keep this post relatively neutral because I know that there're many factors that I can't control for, that could have impacted this test, but it seems this change is neutral at worst and beneficial for many sites.

Three-vote-close/reopen is not, as I mentioned in the original announcement of this test, a perfect solution. It presumes that there are at least three people using the site who are willing to put in the time and effort to review posts and close the ones that need to be closed. Without that, this test can't be successful. We are looking into other options that will help with that. As Philippe mentioned in his 2021 Q4 Roadmap blog post, I'll be investigating an idea to weight votes for close reasons other than duplicates - this may be an alternative or addition to 3-vote close for sites in various situations. I look forward to talking with y'all about that in the coming weeks.

The Numbers

Note: The query I'm using checks dates relatively - meaning I input days before today (e.g. GETUTCDATE()-210) rather than stating a specific date. Because I didn't document which date I ran the queries on, and thus which date range, there is some variation in whether some site met certain criteria.

I've since reworked the queries a bit so that I can show the data over time, which has made it possible for me to include some charts at the bottom of this post - while I'm only including a few for illustrative purposes here, I'll post them for each site when I make the site-specific results posts on the relevant sites’ metas.

Days checked

• Before: -210 to -150 days before Monday 27 Sept ~ 27 Feb - 30 Apr 2021
• After: -90 to -30 days before Monday 27 Sept ~ 29 Jun - 28 Aug 2021

Table 1 - low review completed group

Site	% Reviewed Before	% Reviewed After	Change		% Closed by Mods before	% Closed by Mods after	Change
Stack Overflow en Español	45%	64%	↑ 19		41.9%	14.4%	↓ 27.5
English Language & Usage	68%	95%	↑ 27		10.2%	18.6%	↑ 8.4
Server Fault	51%	46%	↓ 5		10.1%	5.1%	↓ 4.9
Software Engineering	45%	54%	↑ 9		38.8%	12.3%	↓ 25.5
Arduino	47%	97%	↑ 50		61.3%	94.7%	↑ 33.4
Home Improvement	28%	54%	↑ 26		23.2%	5.4%	↓ 17.7

Table 2 - high moderator-led closure group

Site	% Reviewed Before	% Reviewed After	Change		% Closed by Mods before	% Closed by Mods after	Change
Stack Overflow em Português	86%	78%	↓ 8		95.5%	64.2%	↓ 31.2
Cross Validated	94%	93%	↓ 1		97.1%	92.1%	↓ 5
WordPress Development	61%	65%	↑ 4		76.5%	51.7%	↓ 24.8
Drupal Answers	75%	82%	↑ 7		97.4%	64.1%	↓ 33.4
Artificial Intelligence	86%	82%	↓ 4		97.5%	38.2%	↓ 59.2
Software Recs	86%	90%	↑ 4		100%	100%	0
Anime & Manga	64%	73%	↑ 9		98.7%	85.1%	↓ 13.6

Percentages of completed reviews

For the first six sites (Table 1), we were primarily looking for improvement in the review completion percentages. Of those, during the time periods checked, five improved and one got worse, but only slightly.

These increases are welcome, certainly, but this doesn't seem to be enough on some sites to really get the reviews completed consistently. English Language & Usage and Arduino both made it up to the 90% completion range but the other four sites are still under 70%. While it's likely that some questions will always age out of review due to varying interest in reviewing, I would prefer that sites were above 80-90% completion as much as possible.

That said, the improvement was seen and it seems to be stable. I'll be interested in seeing how this changes over the next six months and whether it can help other sites as much as it did these. What was nice to see was that, even on the remaining seven sites (Table 2) where this wasn't the focus, four saw an improvement in completions and of the three that dropped, two were relatively small reductions.

Percentages closed by mods

We want this to go down. For the most part, it does, particularly on the sites where this was the focus of the study (Table 2), but I think what we're seeing here is that the change is happening but not necessarily as much as the mods may benefit from to lighten their loads. While this change is a significant reduction on some sites, it's non-existent or minimal on some, such as Software Recs and Cross Validated.

The two sites that show an uptick (English and Arduino) also show an increase in review completion, so it's possible that moderators are picking up more reviews after two votes. The query I'm using for this doesn't check whether the mod cast the "final" vote - only whether they voted at all. Arduino had a new moderator join the team on July 20th, right in the middle of the window I'm looking at - so this likely explains the increase. When I look at a similar 60-day window before that, I see mods handling only 44.5% of post closures.

In the tables above, while I'm focusing on “closed by mods,” I did look at the overall close and reopen numbers to see if there was any change in reopens - there's generally very small numbers of questions reopened, so I'm not certain the data is as valuable. What I do think is worth looking at is whether there was a change in the number of reopened questions as a function of closed ones though that doesn't necessarily indicate that users were doing more of this.

Table 3 (all test sites)

Site	Questions closed before	Questions reopened before	Questions closed after	Questions reopened after
Stack Overflow en Español	1172	20	1588	43
English Language & Usage	1010	23	1395	128
Server Fault	447	1	468	7
Software Engineering	363	4	341	7
Arduino	93	1	414	12
Home Improvement	108	1	129	4
Stack Overflow em Português	3983	77	2658	29
Cross Validated	1478	99	1034	63
WordPress Development	557	9	395	5
Drupal Answers	272	5	153	11
Artificial Intelligence	118	0	68	2
Software Recs	37	3	44	2
Anime & Manga	77	1	67	2

I'd say that, with the exception of English and a small uptick on Drupal, most of these numbers were relatively consistent, so we can safely say that reopen votes generally aren’t affected.

Pretty Pictures:

A few notes - I'm choosing a few sites to show these images for since these graphs over time can do more to show trends than my static 60 day numbers that, well - so many things can cause it to fluctuate - time of year, changes to review process, COVID etc. I'm including dates from February of 2020 through late September 2021. You can click on any of these images to view the full-sized one.

Reviews completing

These charts show percentages on the vertical axis (note that when sites hit 100% the graph tops out at 120%) over time in weeks on the horizontal axis. The "pending" status indicates reviews that are currently in the review queue, so it's expected to only see anything in the last two weeks that's still pending.

English Language & Usage

On EL&U, this is sort of the best-case scenario for these tests - it's what I'd hope would happen on any site - there's a relatively clear indication that the site has struggled to keep up with review tasks over time but this change leads to a consistent completion of tasks. There are more “leave open” reviews (the light blue line at the bottom), too - while this could mean a number of things, it does indicate that people aren't just closing everything with their new-found lower number of people needed to close.

Stack Overflow en Español

SO en Español is quite different - while there's an uptick and a trend in improved percentages initially, in recent weeks there seems to be a drop in completed reviews - it'd be worth understanding what's changed there. Hopefully this is a temporary drop and we'll see it pop back up over time.

Software Engineering

From the early parts of the chart, it's clear that Software Engineering has been struggling with low completion rates for review tasks for a while. While this change wasn't a huge win that brought the site up to 100% completion, it's clear from the numbers that their lows now are about the same or above their highs before the change - so this feels like a reasonable improvement overall.

Server Fault

Server Fault had a much more modest response to the change. While their completion rates are consistently above 40% now, which they haven't been since August of 2020, they're also rarely above 65%. This graph leaves me wondering what happened in August 2020 to impact the reviewing on the site.

Moderator vs User completion

These graphs are for roughly the same period of time as the prior ones - for reasons™, this uses a lookback in days (GETUTCDATE()-605 from 28 September 2021) rather than being set to a specific date range. This graphs number of posts closed on the vertical axis and time in weeks on the horizontal axis.

In the grand scheme of things, this felt like a smaller "win" than low completion rate. While Table 3 above shows consistent reduction in closure entirely, most of these sites saw an increase in reviews completed, which perhaps indicates that there were fewer posts nominated for closure. This could mean that fewer posts were close-worthy or that mods were less likely to unilaterally close a post after this change went into effect.

It's worth saying at this point that we don't ever expect moderators to close zero questions - there will always be times, particularly on smaller to medium-sized sites where moderators see posts that clearly should be closed, whether that's duplicates, blatantly out of scope questions, or low quality questions that need to be made clear. Unlike the review completion, it's OK if mods are doing 10-50% of the closures - what we don't want to see is them doing all of the work on their own.

Stack Overflow em Português

This was the largest site we ran these tests on and Table 3 above shows a reduction in questions closed during the 60 day period reviewed - and that seems to be confirmed in the trends here, though the control period seemed to be one of higher-than-average closure numbers (~450-500 per week vs ~300-450 per week). Regardless of the total numbers of posts closed, the graphs clearly show that this is the first time in recent history when users have been consistently getting 50-150 closures per week, whereas before May 2021, users generally closed between 10-60 questions per week. Moderators are still doing a decent amount of closing but they've got some help from community members now.

Artificial Intelligence

In contrast, AI was one of the smaller sites we tested this on, and I see a good indication of increased community participation. I'm presenting two graphs here as an outlier week in early 2021 makes it difficult to see the change in recent months, so the second graph narrows the lookback to 235 days. There has been a reduction in questions closed but, with only a small 4% drop in percentage of review tasks handled, that could mean that fewer questions needed to be closed or fewer questions were nominated for closure.

WordPress

This graph seems to show that WordPress has made a pretty sizable change in community closing over the past few months - prior to this change, the community was closing between 1-25 questions per week on average with mods doing the bulk of the 35-75 average closures. While the number of closures per week seems to vary a lot, community members are more frequently closing 25-60 per week while the moderators are having to act on 10-50, a much more even balance.

Because the closures vary so much on WordPress, I'm also including a smoothed monthly view, which shows the community participation a bit more clearly.

Software Recommendations

Having run a similar test on Hardware Recommendations, I was curious whether this change would benefit Software Recs - while it's possible that users are doing more to help out by casting that first and second vote to close, it seems like the moderators are still doing the bulk of the work to actually close questions. I'll be interested to look into this more closely as I'm concerned that the results on this site may indicate that there's a site size or engagement level at which it's simply unlikely that the community can do the work of closing posts, even with a lower number of votes needed.

As you may have noticed in the table above, both before and after this change, moderators were closing 100% of posts closed on Software Recs and this seems to be the general case. The line that pops above the bottom on this one isn't community closures like it is on many of the other sites - it's moderator reopens. Because of the small number of post closures and the large variation, I'm going to show by month rather than week.

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I have a ton more graphs I can share but this post is huge as it is - I'll be making site-specific posts over the next week or so with the info above as well as additional info where it was requested. I'll also be using the information I have to start 3-vote close/reopen on the other sites that have requested it. In general, I don't see any indication of negative impact.

I'd like to thank you all for your patience as I got this project moving and the data assembled. I'd also like to say thanks so much to Shog9 for the queries I've used to make the tables and graphs above as well as Nicolas Chabanovsky for creating a bunch of new queries that I'll be using in the per-site posts. Additionally, thanks go to Slate for helping me review the queries and ensure they were showing what we intended.