When a manager wants to motivate an employee to reach her goals, it isn’t enough to simply encourage her. Instead, ask her to explain how she intends to do it.

Prodding someone to explain how they intend to follow through is good for converting intentions into actions, says Todd Rogers, a Harvard psychologist who conducted an experiment with different groups of voters prior to an election. One group was simply encouraged to vote, and a second group was asked if they intended to vote. A third group was asked both questions, and they also were asked three additional questions: What time do you plan to vote, where will you be traveling from, and what will you be doing before you vote?

After the election, Rogers matched participants’ names to municipal voter-turn lists and found that the highest turnout was in the group that had been asked specific questions about their plans to vote. In a phone interview, Rogers said people are more committed to follow through on things that are time consuming, and voting can require juggling schedules, finding a babysitter, being late for work.

It’s also likely that people made they sure voted because they had publicly declared their intent to do so. Research has found that people feel a need to be consistent by living up to their commitments.

But can a manager ask people to provide a plan without sounding demanding or parental? Sure, Rogers says. Just be honest with people; sometimes it helps to have a plan. “I don’t think it comes off as hostile or aggressive; I’m trying to help them. It’s facilitating follow-through.”