Polls and Bias

 Polls are essential to any politician but they can also be terribly misleading.

Its very hard to construct a poll that has no bias.  Bias can get into polls unintentionally or intentionally.  For example suppose you put on-line polls at the end of news articles.  Well the only people answering that poll are the people who read that article.  So suppose its a poll about a foreign situation such as Afghanistan.  People who have no interest in that country are unlikely to be part of your poll since they probably won't read the news article.  So the answer has a bias built in, not bad just inevitable.

It is also important about how you structure the questions.  I get campaign mail from both major parties and sometimes they include a poll about what priorities they should pursue.  Often what I would suggest isn't part of the survey.  For example if the question is something along the lines of what method should we use to reduce the deficit, it assumes I want to reduce it.  Even if I do the suggestions are generally tailored to things that party favors.  

We also have some polls conducted by independent third parties who honestly try to eliminate bias from the people surveyed and the questions asked.  They are generally better but certainly not perfect.

The one bias they cannot overcome is that they can't sample who won't answer polls.

What way does that bias swing?  We have no way of knowing since they won't answer polls.  We can speculate but it adds uncertainty.  

Still polls do capture some points of view at a specific time and that is an unavoidable bias.  The further away an election is the less reliable the polling is.  Opinions change over time.

They just do.