How, Where and When to Caucus in Iowa on Monday

The Iowans who will brave frigid temperatures Monday for the first test of support for Republican presidential hopefuls will be caucusing — a process that’s distinct from other ballot-box affairs.

Unlike in other elections, Iowa’s Democratic and Republican parties, not the state’s government, organize and run the caucuses. And members of the two parties will conduct business a little differently.

Once participating Republican voters arrive at the caucus precinct, they must check in with precinct workers, who will verify that they are eligible to participate. (Only registered Republicans may participate in G.O.P. caucuses, but party rules allow unregistered voters, Democrats and independents to register or switch their party affiliation at the caucus site.)

Then, the caucusgoers will elect a chair and secretary to preside over the event. Supporters of each candidate will speak to the caucus, pitching their peers on why they should support their preferred candidates.