Gallup Tracking Poll Thread [Obama vs McCain]

[J. J.]

Good, no Palin-mentum so far.

I had the fear once this fundie is seen by 70 Mio. people on TV, the Mccain numbers would increase, but not so this time ...

You have only one day of polling and the 'bots closed slightly.

[J. J.]

It might be noise or the beginnings of a trend.  We'll see.

[J. J.]

It might be noise or the beginnings of a trend.  We'll see.

I have never once heard you say an Obama gain of a point (or an Obama gain of ~0.07 for that matter) may be the beginning of a trend.

I think I've posted a number of times to ignore McCain increases mid-week, because he's tended to go up mid-week.  I'm interested in things that go against patter, like a smaller Obama lead on weekends.  And I'm more concerned if McCain drops in the Wednesday, Thursday, or Friday Gallup polls.

In short, if nothing in the race changed, I'd expect Obama to be either holding or increasing on this poll today.  That didn't happen.  That might be noise, or it might be something else.

[J. J.]

It might be noise or the beginnings of a trend.  We'll see.

Nothing whatsoever happened to justify any trend to McCain. 159,000 jobs were reported lost Friday

Dave

Why do you think I said, it could be noise. 

There were several other things, the bailout, the VP debate.  Noise or trend, well to early to tell.  I do start looking when McCain goes down mid week and Obama goes down over a weekend on Gallup.

[J. J.]

So much for JJ's "trend"...

I said we'll have to wait and see, not a "trend."

Obama basically should be going up on Gallup.

[J. J.]

LOL. Another italicized "should" from J. J.

Because you apparently cannot understand it.  If McCain, in Thursday's, Friday's, or Saturday's Gallup numbers, drop, that is big news, because McCain tends to do a bit better in those polls. 

If Obama, in Sunday's, Monday's, or Tuesday's Gallup numbers, drop, that is big news, because Obama tends to do a bit better in those polls. 

Not much for either candidate, but a bit.

If McCain's midweek numbers go up a little, I'm not going to get too excited.  If his numbers continue at the same level, I'm going to get depressed.

[J. J.]

But the weekend/weekday bounces are just a figment of your imagination.

Except other people noticed them on Gallup.  He's one from an Obama supporter on DU.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=132x5393055#5393230

[J. J.]

Could be a pro Obama sample.  Wait for the next polls.

[J. J.]

So, as of October 8, Obama currently leads, in tracking polls*, McCain from +1 to +11

Average lead: 6% (rounded)

* Batteground (+4), Diageo-Hotline (+1), Gallup (+11), Rasmussen (+6), Research 2000 (+10) and Zogby (+2)

Those differences are just crazy. I don't know what to conclude at the moment, but since Rasmussen sits in the middle, maybe they're on to something?

It's not hard to look at these relatively objectively. First of all, toss Zogby, it's worthless. Diageo I have had some faith in, but they've been prone to big swings, so I wouldn't pay a whole lot of attention to them. While initially I was willing to give benefit of the doubt to the DKos tracker, it's clear they've been fiddling with the partisan weights, so scrap it. Battleground has had weighting problems this whole time, so I have no faith in them even though they've fixed some of their most egregious problems.

So it's really just Gallup and Rasmussen. And 8-9 points feels reasonable right now.

Diageo Hotline had what looks like a bad sample drop out.  Other than that, it isn't too unstable.  I am, however, not too familiar with its track record, so I'm reserving judgment on it.

Either Gallup or Rasmussen has a bad sample.  It's too soon to tell, but look for one of them to shift dramatically.

[J. J.]

Or they both do and will soon be regressing to the mean.

Actually, the odds are 1 in 400 that this will happen.

[J. J.]

Or they both do and will soon be regressing to the mean.

Actually, the odds are 1 in 400 that this will happen.

Based on what?

1 in 20 polls is an outlier.  For each poll to be an outlier, that's 1 x 1 to 20 x 20 to 1 to 400.

One appears to be an outlier, one isn't.  For both to be an outlier, the odds are 1 to 400.

[J. J.]

Or they both do and will soon be regressing to the mean.

Actually, the odds are 1 in 400 that this will happen.

Based on what?

1 in 20 polls is an outlier.  For each poll to be an outlier, that's 1 x 1 to 20 x 20 to 1 to 400.

One appears to be an outlier, one isn't.  For both to be an outlier, the odds are 1 to 400.

First off, let me preface this by saying there's a reasonable chance that I'm completely wrong - I'm no maths whiz - but I don't see how the odds would be 1 in 400.

By my estimate, it's closer to a 1.8% (so almost 1 in 55) chance that both contain 1 outlier.

Reasoning:
If there's a 5% chance that any particular poll is an outlier, then the odds that 1 of a set of 3 polls is an outlier is 3(0.05*0.95*0.95) = 0.135 (that is, 13.5%).
To calculate the chance that both trackers contain an outlier in their sample, I presume one should multiply 0.135 by itself giving a result of approximately 0.018, or a 1.8% chance that both contain an outlier in their 3 day samples.

Anyway, as I say there's a reasonable chance that my reasoning is farcically wrong, but if someone could clarify all this, I'd appreciate it.

I'm looking at the odds that there is a "bad" sample.  That is about 1 in 20.  That will screw up three days of polling, but that isn't what I'm looking at.  I'm just interested in the bad sample.  The odds on both happening on the same day are 1 to 400.

You can argue that it would be 1 in 6 2/3 that this be in a three day sample. That two sets of three day samples would both contain a bad sample is above 44 to 1.

Therefore probably both do not contain a bad sample, though one may.  The outlier could be very well be Rasmussen; we'll probably know which one is the outlier by Saturday, if not sooner.

[J. J.]

For the question of whether it's within MoE it doesn't matter.

Well maybe I missed something but as far as I can tell ,that's all JJ was talking about. yes we obviously have to assume the pollsters conducted a perfectly random sampling and were able to measure the results 100% accurately. Neither is true of course, but you can throw out the polls altogether if these effects cannot be assumed to be small.

You are correct.  I'm suggesting that either Rasmussen or Gallup has a single day sample that is outside of the MOE.  It happens, and it doesn't mean either Rasmussen or Gallup have fallen from grace.  This effect is to be expected. 

We should know which one is wrong by no later than Saturday.  Just chill until then, everyone. 

[J. J.]

Since Obama's been 11 up in Gallup two days in a row, it's obviously not just one day of a bad sample. It would have to be at least two days worth.

The sample stays in for three days.  It does in Rasmussen as well.

That's why I've been saying we should wait until Saturday.  If either the 'bots or Gallup has a bad sample, it will drop out by then.

[J. J.]

I suspect there is a bad sample (possibly Tuesday's sample) that was overly pro-Obama.

[J. J.]

I suspect there is a bad sample (possibly Tuesday's sample) that was overly pro-Obama.

Which probably means Obama is down to 6-8 tomorrow.

On Gallup, yes.  If there is drop of 1-3 points on Gallup for Obama tomorrow, I won't be celebrating.

[J. J.]

Saturday, October 11:

Obama: 51 (nc)
McCain: 42 (+1)

Expected, maybe even a slight uptick for Obama, maybe.

[J. J.]

Saturday, October 11:

Obama: 51 (nc)
McCain: 42 (+1)

Expected, maybe even a slight uptick for Obama, maybe.

Expected?  You said you half-expected a drop of 4+ points.

Instead, the two polls are beginning to converge, Rasmussen up and Gallup down, like I said.

I suspect there is a bad sample (possibly Tuesday's sample) that was overly pro-Obama.

Which probably means Obama is down to 6-8 tomorrow.

On Gallup, yes.  If there is drop of 1-3 points on Gallup for Obama tomorrow, I won't be celebrating.

I expected a 1-3 point drop, just do to a skewed sample.  It happened.

Note I'm saying an Obama trend upward, maybe because his numbers have not dropped up the upper edge of this range.

Boy, Lunar, I'm saying that Obama might be doing better than the polling shows, and you get upset with me.

[J. J.]

My bad sir.  I guess I misunderstood, I thought you meant by "not celebrating" that you meant about your own prediction!

Right now, the gap is 9 points.  I'll be very much surprised if the gap between the two candidates decreases.

[J. J.]

My bad sir.  I guess I misunderstood, I thought you meant by "not celebrating" that you meant about your own prediction!

Right now, the gap is 9 points.  I'll be very much surprised if the gap between the two candidates decreases.

4 - 5% the day before election?

I was referring today's Gallup, which will get at 1:00 PM; that would be four days of decreasing and any single bad sample would be out.

I would be surprised if the gap narrows today.

[J. J.]

I am surprised. 

[J. J.]

Four point drop for Obama since Thursday.  The almost has to have been a bad sample in that.

So if we forget about DailyKos and forget about Battleground, the remaining 4 polls are remarkably close now. Rasmussen and Zogby has Obama at +6, Gallup at +7 and DiegeoHotline at +8.

Forget Zogby (PLEASE!).  Hotline was all over the place.  6-7 Obama?

[J. J.]

So if we forget about DailyKos and forget about Battleground, the remaining 4 polls are remarkably close now. Rasmussen and Zogby has Obama at +6, Gallup at +7 and DiegeoHotline at +8.

That's "remarkably close"?

Compared to the results of 3 or 4 days ago when some polls had Obama up a single point and others at +12 - absolutely!

And a three point range over three polls is fairly close.

[J. J.]

So if we forget about DailyKos and forget about Battleground, the remaining 4 polls are remarkably close now. Rasmussen and Zogby has Obama at +6, Gallup at +7 and DiegeoHotline at +8.

That's "remarkably close"?

Compared to the results of 3 or 4 days ago when some polls had Obama up a single point and others at +12 - absolutely!

And a three point range over three polls is fairly close.

Four polls. And yes indeed.

I refuse to count Zogby. 

[J. J.]

We now have Rasmussen and Gallup moving in opposite directions.  Wait until Wednesday or Thursday.