this post was submitted on 09 Sep 2024
192 points (84.3% liked)

News

23275 readers
3398 users here now

Welcome to the News community!

Rules:

1. Be civil


Attack the argument, not the person. No racism/sexism/bigotry. Good faith argumentation only. This includes accusing another user of being a bot or paid actor. Trolling is uncivil and is grounds for removal and/or a community ban. Do not respond to rule-breaking content; report it and move on.


2. All posts should contain a source (url) that is as reliable and unbiased as possible and must only contain one link.


Obvious right or left wing sources will be removed at the mods discretion. We have an actively updated blocklist, which you can see here: https://lemmy.world/post/2246130 if you feel like any website is missing, contact the mods. Supporting links can be added in comments or posted seperately but not to the post body.


3. No bots, spam or self-promotion.


Only approved bots, which follow the guidelines for bots set by the instance, are allowed.


4. Post titles should be the same as the article used as source.


Posts which titles don’t match the source won’t be removed, but the autoMod will notify you, and if your title misrepresents the original article, the post will be deleted. If the site changed their headline, the bot might still contact you, just ignore it, we won’t delete your post.


5. Only recent news is allowed.


Posts must be news from the most recent 30 days.


6. All posts must be news articles.


No opinion pieces, Listicles, editorials or celebrity gossip is allowed. All posts will be judged on a case-by-case basis.


7. No duplicate posts.


If a source you used was already posted by someone else, the autoMod will leave a message. Please remove your post if the autoMod is correct. If the post that matches your post is very old, we refer you to rule 5.


8. Misinformation is prohibited.


Misinformation / propaganda is strictly prohibited. Any comment or post containing or linking to misinformation will be removed. If you feel that your post has been removed in error, credible sources must be provided.


9. No link shorteners.


The auto mod will contact you if a link shortener is detected, please delete your post if they are right.


10. Don't copy entire article in your post body


For copyright reasons, you are not allowed to copy an entire article into your post body. This is an instance wide rule, that is strictly enforced in this community.

founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] logi@lemmy.world 7 points 2 months ago (1 children)

Probability is useful because it can make predictions that can be tested against reality.

Yes. But you'd have to run the test repeatedly and see if the outcome, i.e. Clinton winning, happens as often as the model predicts.

But we only get to run an election once. And there is no guarantee that the most likely outcome will happen on the first try.

[–] FlowVoid@lemmy.world -3 points 2 months ago (1 children)

If you can only run an election once, then how do you determine which of these two results is better (given than Trump won in 2016):

  1. Clinton has a 72% probability of winning in 2016
  2. Trump has a 72% probability of winning in 2016
[–] BreadstickNinja@lemmy.world 3 points 2 months ago (1 children)

You do it by comparing the state voting results to pre-election polling. If the pre-election polling said D+2 and your final result was R+1, then you have to look at your polls and individual polling firms and determine whether some bias is showing up in the results.

Is there selection bias or response bias? You might find that a set of polls is randomly wrong, or you might find that they're consistently wrong, adding 2 or 3 points in the direction of one party but generally tracking with results across time or geography. In that case, you determine a "house effect," in that either the people that firm is calling or the people who will talk to them lean 2 to 3 points more Democratic than the electorate.

All of this is explained on the website and it's kind of a pain to type out on a cellphone while on the toilet.

[–] FlowVoid@lemmy.world 1 points 2 months ago* (last edited 2 months ago)

You are describing how to evaluate polling methods. And I agree: you do this by comparing an actual election outcome (eg statewide vote totals) to the results of your polling method.

But I am not talking about polling methods, I am talking about Silver's win probability. This is some proprietary method takes other people's polls as input (Silver is not a pollster) and outputs a number, like 28%. There are many possible ways to combine the poll results, giving different win probabilities. How do we evaluate Silver's method, separately from the polls?

I think the answer is basically the same: we compare it to an actual election outcome. Silver said Trump had a 28% win probability in 2016, which means he should win 28% of the time. The actual election outcome is that Trump won 100% of his 2016 elections. So as best as we can tell, Silver's win probability was quite inaccurate.

Now, if we could rerun the 2016 election maybe his estimate would look better over multiple trials. But we can't do that, all we can ever do is compare 28% to 100%.