logoalt Hacker News

rurpyesterday at 8:33 PM7 repliesview on HN

I had complaints about 538, especially the early days, but don't understand this critique at all. A 30% chance hitting is completely unremarkable, and it was a perfectly reasonable reading of the evidence at the time. Nate isn't wrong that conventional wisdom was way off, with even supposedly statistical models giving Hillary a 99% chance of winning.

Elections, like many things, have some inherent uncertainty. A several point polling error is normal, so a candidate who is down a couple points on election day has a decent shot of winning.


Replies

ngriffithsyesterday at 8:57 PM

Discussion of stats models is always complicated by the fact that a lot of people will read "30%" as a "no" prediction and claim your model is wrong if the thing happens. On the one hand, one strategy is to "hide" the numbers a bit behind a blaring headline that says "we are not sure!!" It's a bit of an art to decide when to be "sure" or not. On the other hand, in research for example you can just say screw it, I care if the correct people are correct, not if a bunch of wrong people are wrong.

I feel like the correct strategy for 538 when it was actually niche was to be precise, but then it went viral and maybe should've hit the IDK button much harder and more often after that.

show 3 replies
lacewingyesterday at 8:55 PM

I don't understand why this is surprising. People didn't go to FiveThirtyEight to marvel the science behind it. The science was just supposed to give you what you came there for: the actual election results.

In the end, it turned out that predicting elections is still very hard, and that for all the fanfare, FiveThirtyEight performed only slightly better than what you could find in any other reputable newspaper, so it kinda lost its appeal.

show 4 replies
Sparkle-sanyesterday at 9:41 PM

I can't find the source anymore since 538 is no more, and I recall Nate even describing what could (and did) happen, which was that one swing state moving to the right had a high likelihood of them all moving to the right.

show 1 reply
Retricyesterday at 8:38 PM

Not just that, predictions also impact voter participation.

munchleryesterday at 8:53 PM

I think this is all true, but it dodges the bigger issue. A presidential election has a binary outcome: yes/no, win/lose. If your statistical model doesn’t contain this single bit in its output, then it doesn’t meet the minimum requirement for being a prediction.

Now you might say that it was on me as a consumer to understand this in 2016, but I remember the look of total shock on Nate Silver’s face when he called the winner on live TV that night, so clearly he didn’t really understand it either. Lesson learned for all of us, I guess.

FergusArgyllyesterday at 9:43 PM

It was 30% in the end, before the nomination it famously gave him a 2% chance of getting nominated. All the talk about 30% is disingenuous

https://en.wikipedia.org/wiki/FiveThirtyEight#2016_U.S._elec...

show 1 reply