September update: Community Ads are now live network-wide. All ads with a score of 6 or higher, or with a score of 4 or higher and no downvotes will be displayed (except for any that have a note from the CM Team explaining why it wasn't selected). Go to the main post on MSE for a list of the ads that are being displayed. And stay tuned for 2022's edition for the next opportunity to submit more ad proposals!

AUGUST NOTE: This post has now been locked and new submissions are not being accepted. Ad submissions are now undergoing review by the Community Team, and this question will be updated once the ads are live.

We're almost halfway through 2021, and in case you missed it, Community Promotion Ads are gonna be a bit different this time! TL;DR: submit and vote for ad proposals before August 2nd!

Community Ads are community-vetted advertisements that will show up on the main site, or on other sites in the network. They can show up in the right sidebar, or in banners in question pages. The purpose of this question is the vetting process. Images of the advertisements are provided, and community voting will enable the advertisements to be considered by the Community Management Team to be displayed.

### Why do we have Community Ads?

This is a method for the community to control what gets promoted to visitors on the site. The goal of this initiative is for future visitors to find out about the stuff your community deems important. This also serves as a way to promote information and resources that are relevant to your own community's interests, both for those already in the community and those yet to join. You may want to promote external resources, or Meta guidance for newcomers, for instance.

This initiative has an added goal of providing your community with an opportunity to showcase exemplary questions from your main site, as well as frequently-linked-to guides from your Meta site. While the latter makes sense to be shown solely on this site, the former can be shown all across the network. These should avoid hot button topics, and instead focus more on evergreen questions that show what your community’s all about.

### Why do we reset the ads?

Some services will maintain usefulness over the years, while other things will wane to allow for new faces to show up. Resetting the ads every year helps accommodate this, and allows old ads that have served their purpose to be cycled out for fresher ads for newer things. This helps keep the material in the ads relevant to not just the subject matter of the community, but to the current status of the community. Historically, we've reset the ads every year — since this is the first run of a new format, we'll run the ads collected in this post through the end of 2021 and reassess the rotation cycle then.

The community ads have no restrictions against reposting an ad from a previous cycle. If a particular service or ad is very valuable to the community and will continue to be so, it is a good idea to repost it. It may be helpful to give it a new face in the process, so as to prevent the imagery of the ad from getting stale after a previous exposure.

### Are there restrictions to the ads I can post?

All proposed ads need to abide by our Code of Conduct. Our ad creative guidelines also generally apply (note that the first 2 bullet points on the “Tracking” section do not apply, and a lot of the guidelines surrounding claims, comparisons, proof, etc., while still applicable, may not be particularly relevant). Finally, ads can not be promoting products nor soliciting programmer time or resources for: knowledge sharing or collaboration tools for technologists, or for sites where ad buyers are primarily targeting technologists.

### How does it work?

The answers you post to this question must conform to the following rules, or they will be ignored:

2. All answers must be in one of the below formats:

1. If you have an image for the ad you want to display on this site (must be the case for ads to external sources):
[![Image name. Example: "community_ad_name_300x250"][1]][2]

[1]: https://image-url
[2]: https://clickthrough-url

1. If you want to create an ad for a question from your main or meta site, to be advertised on this or other sites in the network (staff will generate a frame for the ad with this site's theme, for brand consistency):
Question title
Question URL
Site(s) to be displayed in. Can be:
- "self" for ads to be displayed on this site
- "all" for ads to be displayed all over the network
- a specific subset of sites

3. Please do not add anything else to the body of the post. If you want to discuss something, do it in the comments.

### Image requirements

• The image that you create must be 300 x 250 pixels for right sidebar ads or 728 x 90 pixels for banner ads. Images can be double that if high DPI.
• Must be hosted through our standard image uploader (imgur)
• Must be GIF, PNG, or JPG
• No animated GIFs
• Absolute limit on file size of 150 KB
• If the background of the image is white or partially white, there must be a 1px border (2px if high DPI) surrounding it.

### Selection process

This post will remain open for ad submissions and voting until August 2nd. At that point, the question will be closed/locked, and no more ad submissions will be accepted. For ad submissions to be considered for selection by the Community Management Team, they must have a minimum score of 6 at the time the post was closed/locked for submissions. Given this is the first run with this new format, we may adjust the score threshold to be a bit lower if we see ads struggling to get to it (especially if the ads are not getting downvotes) by the time submissions and voting are closed.

### Reporting statistics

Once this cycle is over, at the end of 2021, the Community Management Team will provide you with reporting statistics, as described in the "reporting" section of this post.

Feel free to use the question's comment section to ask for any clarifications.

• No one will ever bother proposing ads. To reasons unknown to me, the community shoots down most proposals Jun 17, 2021 at 21:25
– whuber Mod
Jun 29, 2021 at 20:45
• @whuber I'd love to be proven wrong on this, but community ads have very high rejection here, and I have no idea why. Last year three ads were proposed, two reached threshold. In 2019, 4 ads were proposed, two reached threshold again. In 2018, 8 ads were proposed (counting deleted ones), 3 reached threshold. Jun 29, 2021 at 22:29
• @Firebug Characterizing those statistics as "shoots down most proposals" seems exaggerated. It's a feature of the system that not all proposals will receive enough votes. Your initial comment seems like an attempt to discourage people from proposing or voting ads, which--if successful--would merely be self-serving. That makes it hard to interpret it as a constructive contribution to this thread.
– whuber Mod
Jun 30, 2021 at 13:21
• @whuber This is mostly a rant. The tone is simply due to my current feeling towards how this community treats community ads. I see no clear pattern across all years I looked into. Most don't receive comments, there is no discussion threads for ads, and also most don't reach threshold. I hope some more ads pass threshold this time, but, with the exception of questions (which were not so straightforward to propose in other years), we already see the damage (only two original proposals, and both have been proposed in the past). Jun 30, 2021 at 14:10
• @Firebug This is as good a place as any for a rant, so I have no objections to that. But your remarks appear to rely on the implicit premise that all ad proposals are good and ought to be voted up. As someone who has, over the years, looked at every one of those proposals and decided whether or not to vote, my opinion differs: some are not worth voting up and I would not like to see them reduce the frequency of appearances of the more worthy ads.
– whuber Mod
Jun 30, 2021 at 15:49

Why is accuracy not the best measure for assessing classification models?

Why is accuracy not the best measure for assessing classification models?

Site(s) to be displayed in: all

• This one is great, not only because it attracts users with relevant interest, but also because it is something so often misused by those familiar with only the computational side of statistics. Jul 15, 2021 at 18:31

Problems with pie charts

Problems with pie charts

Site(s) to be displayed in: all

• I support making our high-quality, broad interest questions widely visible & thank you for taking the initiative to collect this list together. But I notice that for each of these suggestions includes "Site(s) to be displayed in: all". I wonder if these questions are really interesting to all of Stack Exchange. For instance, Arqade might have some ML/stats folks among its readers, but those readers are also likely participants on the ML/stats fora. Would it be better to limit distribution to just SO, DS, and AI?
– Sycorax Mod
Jun 30, 2021 at 16:47
• @Sycorax: I don't know. If (1) there's no positive harm in having a question shown on a site where it turns out no-one's interested, & (2) if there isn't a fixed quota of C.V. questions to be distributed across other sites (so we'd get more bang for our buck from concentrating on the likely sites), then we might as well display them on all. Jun 30, 2021 at 18:56
• A fair point! I don't have strong feelings either way.
– Sycorax Mod
Jun 30, 2021 at 19:36
• @Sycorax: If we did go the way of picking sites, it still might be a good idea to cast a wider net than SO, DS, & AI. The more applied questions could be relevant to sites concerned with the natural & social sciences; the more theoretical to sites concerned with the formal sciences. Jun 30, 2021 at 22:34
• I cannot see any of these being relevant to the other three sites I use, English Language Learners, Spanish Language, Travel. If SO is one of the selected sites then the international versions of SO might be worth including as many users there can read English even if they prefer to ask in their own language. Jul 22, 2021 at 12:40
• It might be difficult for users here to judge which sites are most interesting for this, maybe the algorithms are better? One site I dis not see mentioned, but which should be included, is economics. Probably others --- astronomy, physics, ,.. Jul 23, 2021 at 14:41

What should I do when my neural network doesn't learn?

What should I do when my neural network doesn't learn?

Site(s) to be displayed in: all

Why do we only see L1 and L2 regularization but not other norms?

Why do we only see $L_1$ and $L_2$ regularization but not other norms?

Site(s) to be displayed in: all

Principled way of collapsing categorical variables with many levels?

Principled way of collapsing categorical variables with many levels?

Site(s) to be displayed in: all

Algorithms for automatic model selection

Algorithms for automatic model selection

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Can simple linear regression be done without using plots and linear algebra?

Can simple linear regression be done without using plots and linear algebra?

Site(s) to be displayed in: all

When if ever is a median statistic a sufficient statistic?

When if ever is a median statistic a sufficient statistic?

Site(s) to be displayed in: all

What are the shortcomings of the Mean Absolute Percentage Error (MAPE)?

What are the shortcomings of the Mean Absolute Percentage Error (MAPE)?

Site(s) to be displayed in: all

When to choose SARSA vs. Q Learning

When to choose SARSA vs. Q Learning