3 ms·

I'm not sure I get why they bracketed the age group so small as 18–21 vs the broader census definition.

• throwaway729 10y ago
  This is the first presidential election for those voters.
• contravariant 10y ago
  I don't get why the bracketed the age group at all. Surely you can just estimate the distribution?
  • tankenmate 10y ago
    You don't really need to estimate the distribution of ages; the electoral roll and the census will give you a distribution with an error that is several orders of magnitude small than the sampling error from the poll. For all intents and purposes the electoral roll and census data is so close to reality that you might as well declare it as such for calculations.
    • contravariant 10y ago
      Well if the idea is to correct for the biased sampling of your poll you actually do need to estimate the distribution of ages in the people you've polled. Dividing them in small groups and calculating the proportion of people in each isn't the best approach though.
      • tankenmate 10y ago
        You don't need to estimate the distribution of the ages of the people you have polled unless of course you don't know the ages of the people you have polled. You have two distributions of ages here; both are known (within reasonable comparatively minute errors), no need to estimate. The distribution of ages of the electorate, strictly not known, but so so close to known compared to all the other estimates you have to deal with. And the distribution of the ages of your pollees, you simply ask them their age (estimating whether they are lying to you about their age is an infinitely deep philosophical hole you'll never get out of).