Polls fall into two categories—the unscientific polls and the scientific polls. The unscientific polls are more casual and offer less-than-reliable results. The scientific polls are more serious (based on thoughtful methodology) and provide more meaningful results.

The “scientific” part of scientific polls comes from techniques worked out to make them more reliable and representative for large societies.

It’s fairly easy to get the general consensus in a room of 300 people. Everybody raise a hand. With a nation of 300 million, it’s next to impossible without some science backing up your polling methods.

When people talk about scientific polls, they usually differentiate between a few types. The differences between these come from their timing, duration and intent or purpose behind them.

Benchmark Polls—These are the first polls you take in a campaign, or the first ones you really count. They’re the ones that establish a kind of baseline for future polling.

Politicians will do benchmark polls at the beginning of political campaigns to see how familiar they are to the public, where they stand in relation to other candidates and how the public feels about them or their political ideas.

Brushfire Polls—These are the little tester polls that you use to see how things are progressing and to test new ideas or directions on the public. Politicians will use brushfire polls to figure out how their public feels about elements of their agenda or new ideas or directions.

Tracking Polls—These are the ones you use to track trends over time. You might use the same poll weekly, monthly or yearly to establish a trend on a certain topic, likely in the same demographic.

Politicians will use tracking polls as major guidelines for their campaigns, constantly tweaking their campaigns based on how their voting public perceives them, as evidenced in the tracking polls.

Push Polls—These are the ones that take an active role in things. Push polls are political tools—politicians use them not to learn what the public is thinking, but to influence it.