In a sense, every post on this site seeks to answer the question of why polls seem contradictory. A good place to start is with the following three posts on the random variation inherent in all sample surveys and what a consumer can do to minimize it (each post has a link at the end connecting to the next post in the series):
Beyond that, much of the variation in political polls comes from the way the pollster defines a “likely voter.” These two questions on the FAQ list deal with two issues that explain much of the systematic variation between polls
Finally, at the most basic level, political campaign polls typically seek to accomplish three tasks. Click on any of these links to display short excerpts of all of the posts in the category in reverse chronological order (most recent first):
Mark Blumenthal is political pollster with deep and varied experience across survey research, campaigns, and media. The original "Mystery Pollster" and co-creator of Pollster.com, he explains complex concepts to a multitude of audiences and how data informs politics and decision-making. A researcher and consultant who crafts effective questions and identifies innovative solutions to deliver results. An award winning political journalist who brings insights and crafts compelling narratives from chaotic data.
