From holiday distractions to winter weather, the people who will be measuring voters' preferences in primaries and caucuses around the nation will be dealing with unprecedented problems. Here's how they plan to do it.
The landline-less are different from regular telephone users in many of their opinions and their numbers are growing fast. Can survey researchers meet this challenge?
As the number of declared presidential candidates grows, followers of early poll readings should bear in mind some caveats. Early frontrunners for the Republican nomination in most of the past seven open contests have gone on to win the nomination, but this year there are two GOP frontrunners instead of one clear leader. On the Democratic side, even when there is a clear frontrunner as there is this year with Sen. Hillary Clinton, the early polls have been less reliable in predicting who will capture the nomination.