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With the presidential election just five weeks away, the only thing predictable about the campaign season is the daily churn of United States electorate polls.

Polls have garnered derision over the last few election cycles, but survey methodologists—including Kristen Olson, director of the University of Nebraska–Lincoln's Bureau of Sociological Research—are always working to improve the science.

Polling methodology is always changing, Olson, an expert in survey methodology, said. Most notably, pollsters have changed the ways polls are conducted over the last two decades. According to a study by the Pew Research Center, in 2000, polling was done almost exclusively by phone.

Today, pollsters rely on text, online and phone surveys, and probability panels that follow a group of voters through a set amount of time during an election campaign. More firms are also gathering the numbers, with the number of active polling firms more than doubled since the turn of the century.

Olson served on committees for the American Association for Public Opinion Research charged with reviewing polling methods and outcomes following presidential elections, which led to changes in how pollsters statistically weight their data and the transparency of firms' methods.

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