OT Unless the percentages match, no such thing as a statistical dead
heat

I've wondered about this off and on, and I once asked on another
newsgroup, but until today, I've never remembered to google it.

http://iase-web.org/documents/papers/isi53/292.pdf

http://boards.straightdope.com/sdmb/...ad.php?t=30816

but non-statistical live colds are ok I'm sure

On Wed, 02 Apr 2014 05:21:27 -0500, philo* wrote:

but non-statistical live colds are ok I'm sure

Absolutely

On Wed, 02 Apr 2014 05:08:26 -0400, micky
wrote:

OT Unless the percentages match, no such thing as a statistical dead
heat

I've wondered about this off and on, and I once asked on another
newsgroup, but until today, I've never remembered to google it.

http://iase-web.org/documents/papers/isi53/292.pdf

http://boards.straightdope.com/sdmb/...ad.php?t=30816


The more I think about this, the more things become clear. When the say
the difference is within the margin of error, is there a 95% chance the
guy who is ahead, is ahead? No. But I just realized that the chance
never goes below 50+%, because if it were lower than 50, the odds would
be that he is behind. And if his poll numbers exceed the other guy, the
odds are he's ahead, not behind.

On Wednesday, April 2, 2014 5:08:26 AM UTC-4, micky wrote:
OT Unless the percentages match, no such thing as a statistical dead

heat



I've wondered about this off and on, and I once asked on another

newsgroup, but until today, I've never remembered to google it.



http://iase-web.org/documents/papers/isi53/292.pdf



http://boards.straightdope.com/sdmb/...ad.php?t=30816

I do a lot of statistical analysis at work. Crunching the numbers is the easy part; explaining the results in terms that non-statisticians will understand is difficult. I agree that "statistical dead heat" is a misleading phrase but it gets the point across to people who don't understand standard deviations, confidence intervals and sampling techniques.

Paul

On 4/2/2014 9:59 AM, micky wrote:
....

The more I think about this, the more things become clear. When the say
the difference is within the margin of error, is there a 95% chance the
guy who is ahead, is ahead? No. But I just realized that the chance
never goes below 50+%, because if it were lower than 50, the odds would
be that he is behind. And if his poll numbers exceed the other guy, the
odds are he's ahead, not behind.

Let's see if I can muddy it up, then...

The probability of the obverse being the true situation is a Type II
error...

--

On Wednesday, April 2, 2014 10:59:39 AM UTC-4, micky wrote:
On Wed, 02 Apr 2014 05:08:26 -0400, micky

wrote:



OT Unless the percentages match, no such thing as a statistical dead

heat



I've wondered about this off and on, and I once asked on another

newsgroup, but until today, I've never remembered to google it.



http://iase-web.org/documents/papers/isi53/292.pdf



http://boards.straightdope.com/sdmb/...ad.php?t=30816





The more I think about this, the more things become clear. When the say

the difference is within the margin of error, is there a 95% chance the

guy who is ahead, is ahead? No. But I just realized that the chance

never goes below 50+%, because if it were lower than 50, the odds would

be that he is behind. And if his poll numbers exceed the other guy, the

odds are he's ahead, not behind.

Consider a poll on candidates Smith versus Jones. We poll one person who picks Smith. Our poll indicates Smith with 100% of the vote, but we wouldn't put much confidence in the result of that poll.

So we poll another person who picks Jones. Now, with a sample size of 2, we have 50% Smith and 50% Jones but how reliable is a poll of two people when there are thousands of people who will be voting?

We go out ringing doorbells again and end up with a hundred responses, 52 for Smith and 48 for Jones, a 4% difference between the two. Based on the sample size and other parameters*, we might find that the results of this poll give us a 99% confidence that the results of the sample are within 5% of the results had we polled the entire electorate.

You could think of it as meaning that Smith should end up with somewhere between 57% (52% + 5%) and 47% (52% - 5%)of the vote and Jones should end up with somewhere between 53% (48% + 5%) and 43% (48% - 5%)of the vote. Since we're 99% confident that either candidate could end up with over 50% and win, it's a "statistical dead heat."

* Here's a good reference on all that: http://en.wikipedia.org/wiki/Sample_size_determination

Paul

On Thu, 3 Apr 2014 06:26:19 -0700 (PDT), Pavel314
wrote:

On Wednesday, April 2, 2014 5:08:26 AM UTC-4, micky wrote:
OT Unless the percentages match, no such thing as a statistical dead
heat

I've wondered about this off and on, and I once asked on another
newsgroup, but until today, I've never remembered to google it.

http://iase-web.org/documents/papers/isi53/292.pdf

http://boards.straightdope.com/sdmb/...ad.php?t=30816

I do a lot of statistical analysis at work. Crunching the numbers is the easy part; explaining the results in terms that non-statisticians will understand is difficult. I agree that "statistical dead heat" is a misleading phrase

Okay, we agree on that.

but it gets the point across to people

No it doesn't. It's misleading, like you said.

who don't understand standard deviations, confidence intervals and sampling techniques.

If you want to get the point across without using fancy words, say
"Smith is probably ahead now, but because we didn't poll every person,
Jones might actually be ahead."

Using the example from your other post, you could say " There's an 80%**
chance that Smith is ahead now and a 20% chance that he's behind.

How's that?

**Whatever the number really is. And maybe I should have included a
1% chance they were tied. I don't know what the chances are for that.


Paul

philo* posted for all of us...

And I know how to SNIP


but non-statistical live colds are ok I'm sure

I have a question: What is the difference between dead heat and live heat?
Inversely dead cold and live cold? I've also heard of dry heat and dry ice
and dry air and dry eyes, etc. How do I fit all this together in my master
plan?

--
Tekkie

Pavel314 posted for all of us...

And I know how to SNIP

standard deviations


Could you explain if I am a standard deviate or substandard?

--
Tekkie

On 4/3/14 8:43 AM, dpb wrote:

Let's see if I can muddy it up, then...

The probability of the obverse being the true situation is a Type II
error...


And you did it without using any ten dollar words.