Almost all polls are worthless, because the decision to respond to the poll is itself a major portion of the signal.
It takes extensive work to get around that problem alone, let alone "viral" and other worthless push-polls - work that even the very best in the industry, at the highest level, can make major mistakes on.
>Almost all polls are worthless [...] because the decision to respond to the poll is itself a major portion of the signal.
But most polls I see are from professional pollsters like Pew or YouGov? For them, correcting for this is opinion polls 101. That's why you see "representative sample". They're not just randomly polling 1000 people and taking the average. They're adjusting for a bunch of other demographic factors as well.
Then you're mostly looking at those who "try" - but if you look wider you'll see polls used way more often than that (think of the companies entirely built around it, customer satisfaction surveys, Facebook "polls", etc, etc).
Doing a proper poll is expensive and (frankly) most of the time is pretty predictable or you can get 90% of the results with 10% of the effort, and most times you don't actually care about the results because you're building it to get a result you want anyway.
(Interestingly enough elections themselves almost by definition have notable discrepancies to a "true" perfect sampling; but it's usually overcome by the sheer volume.)
And there's no clear way to adjust for the most basic factor that people who vote for one candidate are less likely to say so.
In order to account for that, you need you know how many people who are less likely to respond are voting for that candidate. And then you're back to square one.
This is why professional polls have had a consistent bias over the last few years, as this hidden unobservable factor's effect has gotten stronger and stronger.
When they are 3 or 4 percentage points off they are ripped to shreds.
The polls for the recent Brazil elections were about 49% for Lula, the result was 52%, that's a 3 point difference, not a massive error margin. With brexit the polling pointed to about 52% for remain, actual result was 48%.
But those are proper polling companies, not worthless online ones.
Almost all polls are worthless, because the decision to respond to the poll is itself a major portion of the signal.
It takes extensive work to get around that problem alone, let alone "viral" and other worthless push-polls - work that even the very best in the industry, at the highest level, can make major mistakes on.
>Almost all polls are worthless [...] because the decision to respond to the poll is itself a major portion of the signal.
But most polls I see are from professional pollsters like Pew or YouGov? For them, correcting for this is opinion polls 101. That's why you see "representative sample". They're not just randomly polling 1000 people and taking the average. They're adjusting for a bunch of other demographic factors as well.
Then you're mostly looking at those who "try" - but if you look wider you'll see polls used way more often than that (think of the companies entirely built around it, customer satisfaction surveys, Facebook "polls", etc, etc).
Doing a proper poll is expensive and (frankly) most of the time is pretty predictable or you can get 90% of the results with 10% of the effort, and most times you don't actually care about the results because you're building it to get a result you want anyway.
(Interestingly enough elections themselves almost by definition have notable discrepancies to a "true" perfect sampling; but it's usually overcome by the sheer volume.)
And there's no clear way to adjust for the most basic factor that people who vote for one candidate are less likely to say so.
In order to account for that, you need you know how many people who are less likely to respond are voting for that candidate. And then you're back to square one.
This is why professional polls have had a consistent bias over the last few years, as this hidden unobservable factor's effect has gotten stronger and stronger.
> Almost all polls are worthless
Do you have one example of a poll that isn't?
The only poll that matters is the one on election day.
Most professional pollers do a good job.
When they are 3 or 4 percentage points off they are ripped to shreds.
The polls for the recent Brazil elections were about 49% for Lula, the result was 52%, that's a 3 point difference, not a massive error margin. With brexit the polling pointed to about 52% for remain, actual result was 48%.
But those are proper polling companies, not worthless online ones.