This evening, Iowa voters gather in churches, schools, and community centers to debate the relative merits of each 2016 presidential candidate and try to persuade their fellow caucus-goers to support one candidate or another. The caucuses are very different than primaries, and the time commitment and peculiar rules mean that typically only 20 percent of Iowa voters caucus, reports James Rosen at Fox News. Adding to the confusion, Democrats and Republicans caucus differently, with Republicans writing their preference down on sheets of paper and Democrats gathering in groups in different areas of the caucus room. Thanks to a new smartphone app from Microsoft, we will probably know the results Monday night, but if you're curious about how Iowans get to a winner, watch Rosen's report below. Peter Weber