The last-minute training efforts worried some caucus volunteers and raised the specter of reporting glitches like the ones that plagued Iowa.

“I would be the happiest person in the world if everything works, but I am nervous,” said Seth Morrison, a caucus volunteer. “We have a new tool that is untested, then we have a very complex caucus process.”

Another volunteer, who requested anonymity for fear of a potential backlash, said he was encouraged by the training, which he completed Tuesday, and the reporting tools themselves.

It wasn’t complicated “for people familiar with iPads and tablets in general,” he said, in a text. But he added that he was worried about the people “who aren’t comfortable with tablets.”