Comments on: In opinion polls, what does “margin of error” mean?

By: Alan Cooper

Alan Cooper — Tue, 27 Jan 2009 07:59:55 +0000

Well, Erik, I didn’t say “doomed to extinction” so “survival” is not necessarily the issue. And the capacity that I actually claimed was lacking was not a scientific one but rather one of perseverance at a challenging *linguistic* task.

Although it may well be true that our needs for invention and scientific progress can be met by devoting only a small fraction of the population to those tasks, it is also true that in a democracy the ultimate responsibility for political decisions generally rests with the population as a whole.

And to make those political decisions in a way that will not doom us to something very nasty requires an ability and willingness to analyse complicated propositions (and also indeed to understand quantitative statements – but I didn’t say that in the comment you were complaining about).

cheers,
Alan

By: Erik

Erik — Tue, 27 Jan 2009 05:05:19 +0000

Actually Alan,

The continued survival of the species certainly does not require that we all understand the intricacies of of the mathematics or the sciences.

It merely requires that SOME who find it interesting do. I have taken a survey and have found that to a +/- 3% margin of error, with a 95% level of certainty. you are an **** [edited].

Cheers.

By: zac

zac — Tue, 15 Jan 2008 04:17:40 +0000

Hi Alan and thanks for your input. Good to hear from you again.

Something that I meant to mention in my tirade against opinion polls: How many people really understand the question they are being asked?

I see this all the time in education-based polling. In a field that is multi-variable, it is difficult, if not impossible, to determine what actually resulted in an increase (or decrease) in learning.

But when it comes to political polling, it is more straightforward.

Disclaimer: I also conduct polls, but I regard the results (like all educational polling) as having a margin of error of ±50%. They give a general indication of the lay of the land, and that’s all. I am yet to see an educational poll that I am satisfied is “scientifically accurate”.

By: Alan Cooper

Alan Cooper — Tue, 15 Jan 2008 03:38:07 +0000

Hi Zac,
I think your first paragraph overstates the case a bit. A ‘margin of error’ statement *can* be made in a way that is meaningful and accurate. Although ” the percentage of people who believe Y is x% with a margin of error z%” is something that cannot be established by polling (or any other currently known technology), the statement that “the percentage of those selected at random by procedure p who will say that they believe Y when asked in script S is x% with a margin of error of z% at the c% confidence level” is a meaningful and provable statement. It means that if you repeatedly select a bunches of people by procedure p (which probably includes the specific number selected), and present them all with script S, then at the point where you ask whether or not they believe Y, the percentage who say yes will be between (x-z)% and (x+z)% in on average c% of the bunches. The fact that 90% of humanity with a margin of error of 20% don’t have anything like the capacity for parsing the previous sentence is one of the (several) reasons why our species is doomed.