Adventures in probability - Macleans.ca
 

Adventures in probability


 

Michael Veall cautions against reading too much into sudden poll changes.

So even if a party is up say 3.5 percentage points comparing a new poll with a previous poll, if each poll had a margin of error of 3.1 percentage points, the 3.5 percentage point increase should be compared to a margin for error of about 4.4 percentage points. There is a reasonable chance that the party’s vote intention share in the total population did not change at all: all that happened was that the pollsters randomly happened to choose more of the party’s supporters in the second poll.

The margins of errors for changes in leads can be twice as large again. If a party is leading by 5 percentage points in one poll and then by 9 percentage points in the next poll, the margin of error around that 4 percentage point gain could be over 8 percentage points. While probably the lead increased, there is still a significant chance that the lead decreased.


 

Adventures in probability

  1. A pox on all their polls.

  2. A pox on all their polls.

  3. Pseudo populism and pseudo pollism. Just in time for a new 'news' network.

  4. Pseudo populism and pseudo pollism. Just in time for a new 'news' network.

    • I'm watching it right now… wow. Something to behold.

  5. Whenever I read a poll, or hear that a candidate/leader/party is going to win or lose, I always remember that Hunter Thompson almost became sheriff on a platform of peyote and bicycles. The polls never saw that one coming because nobody was polling bicycle-riding peyote fiends. Thompson called it the "Freak Vote."

    The dynamic isn't that different from the youth vote today. They aren't very pollable, since they don't have landlines and tend not to vote. If somebody gets them to turn up and vote though, things change in a hurry and the polls go out the window.

    Now I don't mean to suggest that today's youth are a bunch of peyote-gobbling hippies…they have their own drugs (or at least new names for the old ones) and realize that refusing to wash isn't really a political statement. I am suggesting that if they get their butts out to the polls they can the Fear into us old farts though. Who the hell are we to decide their future?

  6. Whenever I read a poll, or hear that a candidate/leader/party is going to win or lose, I always remember that Hunter Thompson almost became sheriff on a platform of peyote and bicycles. The polls never saw that one coming because nobody was polling bicycle-riding peyote fiends. Thompson called it the "Freak Vote."

    The dynamic isn't that different from the youth vote today. They aren't very pollable, since they don't have landlines and tend not to vote. If somebody gets them to turn up and vote though, things change in a hurry and the polls go out the window.

    Now I don't mean to suggest that today's youth are a bunch of peyote-gobbling hippies…they have their own drugs (or at least new names for the old ones) and realize that refusing to wash isn't really a political statement. I am suggesting that if they get their butts out to the polls they can the Fear into us old farts though. Who the hell are we to decide their future?

    • Who are we? I think we are the older, wiser people who actually have jobs and pay taxes, that's who. I fear the youth vote, to use the old cliche, because young people are all heart and compassion and idealism with no clue nor care for the cost of their ideas simply because they aren't paying for it. It's awfully easy to be a leftist when you are demanding other people pay for your ethics. Anyone over 30 working a job (or two) knows life beats those childish fantasies out of you and that when voters vote themselves money no one wins. Frankly, the idea that youth should have a voice equal to their elders is truly one of the scariest things to me

      • Wow, you shouldn't have eaten that brown acid, dude. I am a leftist. Have a job, have a business, been working my ass off since I was a child. Will keep doing so until I can't. I pay for my own ethics, thanks. Time to re-examine your prejudices, my little buckaroo.

        The thing is that you seem to think ethics are something that can be bought and sold. I'm sure Angry Steve and that Carson fellow agree with you. Ethics…real ethics, not sucking on whatever corporate member lands in your mouth… are something we should encourage in young people.

      • Really?… You DO realize that these young folks are going to be paying for the Conservative Crime bill…the Harper deficit…and fighter jets with no engines for a long time. Let me guess. they aren't " real Canadians" to you…Man you are a scary dude.

    • .
      Of course, you're excluding young people going university business schools. And we know they're parents are more likely to have landlines, and will get polled. We know how THEY are going to poll and of course they are automatically correct for that very (circular) reason. People least likely to be polled are the very landline-less, jobless, and/or shared-accommodation, victims of slash-and-burn econ majors, etc.

      Being a conservative makes life so clear and simple: Right is Right, and wrong is wrong, and people who should not be voting should not be voting, and those who should, should, and, and…because…
      .

  7. Who let a voice of reason speak about polls during an election?

  8. Who let a voice of reason speak about polls during an election?

  9. So Harper has successfully moved us closer to the right wing nuts (republican) in the US. First he had the CRTC rule that the Canadian news could 'purposely' mislead Canadians (Feb. 9, 2011) and he managed this by having us all talk about a 25 year old Dire Straits song because ONE conservative operative complained about a derogitory word in the song. While we were all in an uproar over that ruling they slipped through the 'mislead' the public ruling. Now we have Fox News North…and who is it that the conservatives are saying is American? Harper is a danger to Canadian Sovereignty which is no surprise given he signed it away a few months back. God Bless America and God help Canada!!!

  10. So Harper has successfully moved us closer to the right wing nuts (republican) in the US. First he had the CRTC rule that the Canadian news could 'purposely' mislead Canadians (Feb. 9, 2011) and he managed this by having us all talk about a 25 year old Dire Straits song because ONE conservative operative complained about a derogitory word in the song. While we were all in an uproar over that ruling they slipped through the 'mislead' the public ruling. Now we have Fox News North…and who is it that the conservatives are saying is American? Harper is a danger to Canadian Sovereignty which is no surprise given he signed it away a few months back. God Bless America and God help Canada!!!

    • Clarification: It's already been legal to purposely mislead people in the news. Just look at the Sun Newspapers' smearing of the guy that worked on that CBC vote compass. The only difference is, now with that pesky CRTC regulation out of the way (and I'm not sure that they actually did strike it down, but anyway), you can fake the news on TV too.

        • Nice to see the tin foil brigade is out in force. Still, to correct your misconceptions, the Supreme Court of Canada ruled in 1992 that a person could not be charged with disseminating false information. The CRTC, acting on a recommendation of the pertinent parliamentary committee, simply tried to make our written law reflect the decision of the supreme court. Either way it is not illegal to disseminate "fake news". Live with it.

          • No, we won that battle. The CRTC backed down. They said they were 'relieved'.

      • The CRTC rule for truth in news reporting is STILL there.

        They didn't change it.

  11. Clarification: It's already been legal to purposely mislead people in the news. Just look at the Sun Newspapers' smearing of the guy that worked on that CBC vote compass. The only difference is, now with that pesky CRTC regulation out of the way (and I'm not sure that they actually did strike it down, but anyway), you can fake the news on TV too.

  12. I'm watching it right now… wow. Something to behold.

  13. dont go to a news article. Check out the CRTC site. It was still in the works as of March 1.

  14. dont go to a news article. Check out the CRTC site. It was still in the works as of March 1.

  15. On another note. This is a facebook group circulating among young Canadians.
    http://sh**harperdid.ca.nyud.net/
    type in the obvious letters I had to remove from this web address so I could post on this site.

  16. On another note. This is a facebook group circulating among young Canadians.
    http://sh**harperdid.ca.nyud.net/
    type in the obvious letters I had to remove from this web address so I could post on this site.

    • I wonder what those 'young' Canadians would do when placed in war situations.

      • Unless you're willing to send your wrinkled old butt in their place, I'd suggest all you have to do is look.

    • One must note that they recommend voting Bloc Quebecois, where possible, to stop the Conservatives. Such proud Canadians they must be, too!

  17. I wonder what those 'young' Canadians would do when placed in war situations.

  18. Who are we? I think we are the older, wiser people who actually have jobs and pay taxes, that's who. I fear the youth vote, to use the old cliche, because young people are all heart and compassion and idealism with no clue nor care for the cost of their ideas simply because they aren't paying for it. It's awfully easy to be a leftist when you are demanding other people pay for your ethics. Anyone over 30 working a job (or two) knows life beats those childish fantasies out of you and that when voters vote themselves money no one wins. Frankly, the idea that youth should have a voice equal to their elders is truly one of the scariest things to me

  19. I eagerly await a stunning review of the new Sun news network and how life on earth as we know it will come crashing down around our ears, well for us new-found vote compass liberals anyway.

  20. I eagerly await a stunning review of the new Sun news network and how life on earth as we know it will come crashing down around our ears, well for us new-found vote compass liberals anyway.

    • I'm tuning into it now. Oddly enough, it's available over-the-air where I am; I thought it was going to be cable-only. I didn't think they had the license to broadcast OTA.

      I just tuned it in and caught the portion with David Akin. The content was fine, and what I anticipated. I like Akin, so even though Frum was a little off in what I would have said, it wasn't over-the-top. However, the production quality of that segment was abysmal. The logos were flickering, Frum was out of focus, and the entire segment was blurry and weird. Strangely enough, one of the commercials was the LPC "Stakes" ad! LOL

      The segment that's on right now is much better quality, and what I expected. I can't count the number of times I've heard the word "freedom" so far, however. :)

      EDIT: I take it back, the current segment with Ezra Levant still has the really crappy banners on the bottom that keep flickering, as well as a very bad font. The very bottom ticker font is perfect and the logo is acceptable, but the "Caldwell Account" and actual Headline looks very poor. I assume they'll fix this over the next few days, because that's unacceptable production quality. My grandmother can make a better looking overlay with Windows Movie Maker.

      • It's ok…all they have to do is put a Sunshine Girl out front and nobody will notice.

  21. The CRTC rule for truth in news reporting is STILL there.

    They didn't change it.

  22. Nice to see the tin foil brigade is out in force. Still, to correct your misconceptions, the Supreme Court of Canada ruled in 1992 that a person could not be charged with disseminating false information. The CRTC, acting on a recommendation of the pertinent parliamentary committee, simply tried to make our written law reflect the decision of the supreme court. Either way it is not illegal to disseminate "fake news". Live with it.

  23. Wow, you shouldn't have eaten that brown acid, dude. I am a leftist. Have a job, have a business, been working my ass off since I was a child. Will keep doing so until I can't. I pay for my own ethics, thanks. Time to re-examine your prejudices, my little buckaroo.

    The thing is that you seem to think ethics are something that can be bought and sold. I'm sure Angry Steve and that Carson fellow agree with you. Ethics…real ethics, not sucking on whatever corporate member lands in your mouth… are something we should encourage in young people.

  24. Unless you're willing to send your wrinkled old butt in their place, I'd suggest all you have to do is look.

  25. I'm tuning into it now. Oddly enough, it's available over-the-air where I am; I thought it was going to be cable-only. I didn't think they had the license to broadcast OTA.

    I just tuned it in and caught the portion with David Akin. The content was fine, and what I anticipated. I like Akin, so even though Frum was a little off in what I would have said, it wasn't over-the-top. However, the production quality of that segment was abysmal. The logos were flickering, Frum was out of focus, and the entire segment was blurry and weird. Strangely enough, one of the commercials was the LPC "Stakes" ad! LOL

    The segment that's on right now is much better quality, and what I expected. I can't count the number of times I've heard the word "freedom" so far, however. :)

    EDIT: I take it back, the current segment with Ezra Levant still has the really crappy banners on the bottom that keep flickering, as well as a very bad font. The very bottom ticker font is perfect and the logo is acceptable, but the "Caldwell Account" and actual Headline looks very poor. I assume they'll fix this over the next few days, because that's unacceptable production quality. My grandmother can make a better looking overlay with Windows Movie Maker.

  26. One must note that they recommend voting Bloc Quebecois, where possible, to stop the Conservatives. Such proud Canadians they must be, too!

  27. Does chanting this help you get to sleep Aaron?

    Two weeks until you'll have to cry yourself to sleep on your huge pillow.

  28. Does chanting this help you get to sleep Aaron?

    Two weeks until you'll have to cry yourself to sleep on your huge pillow.

  29. this is just wrong . First of all the MOE is not doubled to compare a lead . In a multiparty system such as canada's try 1.6 as a rule of thumb . The number can be much smaller if we are doing repeated measures over time. Moreover , the increasingly disreputable notion of MOE is under acute pressure . We are best to deal with zones of likelihood and Bayesian inference rather than the flawed .05 test , arbitarily picked to deal with fertilizer and corn fields over a hundered years ago. Finally, the MOE isnt some equiprobable box which sits over the distribution , The likelihood of the outer regions of the margin are FAR more improbable than the central tendency . Does anyone realise that it is just as great an error to inaccurately fail to identify a true effect (type II error) as it is to spuriously fail to reject a false effect (type one error or alpha error). This is actually a nearly hopeless discussion but i get really fatigued with the "experts " missing the key points
    Guest

  30. this is just wrong . First of all the MOE is not doubled to compare a lead . In a multiparty system such as canada's try 1.6 as a rule of thumb . The number can be much smaller if we are doing repeated measures over time. Moreover , the increasingly disreputable notion of MOE is under acute pressure . We are best to deal with zones of likelihood and Bayesian inference rather than the flawed .05 test , arbitarily picked to deal with fertilizer and corn fields over a hundered years ago. Finally, the MOE isnt some equiprobable box which sits over the distribution , The likelihood of the outer regions of the margin are FAR more improbable than the central tendency . Does anyone realise that it is just as great an error to inaccurately fail to identify a true effect (type II error) as it is to spuriously fail to reject a false effect (type one error or alpha error). This is actually a nearly hopeless discussion but i get really fatigued with the "experts " missing the key points
    Guest

  31. Really?… You DO realize that these young folks are going to be paying for the Conservative Crime bill…the Harper deficit…and fighter jets with no engines for a long time. Let me guess. they aren't " real Canadians" to you…Man you are a scary dude.

  32. It's ok…all they have to do is put a Sunshine Girl out front and nobody will notice.

  33. .
    Of course, you're excluding young people going university business schools. And we know they're parents are more likely to have landlines, and will get polled. We know how THEY are going to poll and of course they are automatically correct for that very (circular) reason. People least likely to be polled are the very landline-less, jobless, and/or shared-accommodation, victims of slash-and-burn econ majors, etc.

    Being a conservative makes life so clear and simple: Right is Right, and wrong is wrong, and people who should not be voting should not be voting, and those who should, should, and, and…because…
    .