Facebook is a service that connects friends, families and groups. At least, that’s the way founder Mark Zuckerberg promoted the platform for its first ten years. Today he’s creating a new vision to guide the company for the next ten years. And he’s using an effective leadership method to do it.

Speaking in Chicago at Facebook’s first Communities Summit, Zuckerberg said, “For the last decade we’ve been focusing on making the world more open and connected…We have a responsibility to bring the world closer together.” Zuckerberg then introduced the company’s new mission statement, a vision that will act as the company’s guiding light. Zuckerberg, said Facebook, will exist “to give people the power to build community to bring the world closer together.”

Zuckerberg’s slide summarized the vision in just five words.

Bring the world closer together

One month ago, Zuckerberg articulated the vision in his Harvard commencement speech. The word ‘communities’ appears sixteen times.

“In our generation, the struggle of whether we connect more, whether we achieve our biggest opportunities, comes down to this — your ability to build communities and create a world where every single person has a sense of purpose,” he told the graduates.

As a former Harvard student and a current student of leadership, Zuckerberg might be familiar with the work of Harvard professor John Kotter. Kotter wrote a major paper on why business transformations often fail. Kotter concluded that one critical error that leaders make is failing to communicate a clear and concise vision.

“In every successful transformation effort that I have seen, the guiding coalition develops a picture of the future that is relatively easy to communicate and appeals to customers, stockholders, and employees.” Kotter found that without a clear vision, a leader’s effort to change the direction of an organization will “dissolve” into a list of “confusing and incompatible projects.” Employees will be confused, alienated and demoralized if they see change happening without a clear and compelling statement, much like the one Zuckerberg delivered.

Kotter said transformations fail when a second error is committed. Ineffective leaders under communicate the vision by a factor of ten. “Transformation is impossible unless hundreds or thousands of people are willing to help, often to the point of making short-term sacrifices…Without credible communication, and a lot of it, the hearts and minds of the troops are never captured.”

With two billion users on the Facebook platform, Zuckerberg has transformed the way people connect with one another. Zuckerberg also has transformed himself into a powerful persuader. He won’t fall into the trap of under communicating a vision. In fact, he’s repeating the vision in speeches, presentations, and on Facebook posts.

For example, while visiting a prep school in a tough neighborhood on Chicago’s south side he wrote, “To bring the world closer together, we have to build communities that keep people safe. Some neighborhoods in Chicago have a long way to go, but the students I met today give me hope. We’re going to do everything we can to help more people build communities like their school.”

Earlier in the year Zuckerberg posted a 6,000 word letter which he called, Building Global Community. He wrote, “Going forward, we will measure Facebook’s progress with groups based on meaningful groups, not groups overall. This will require not only helping people connect with existing meaningful groups, but also enabling community leaders to create more meaningful groups for people to connect with.”

In hindsight, the letter provided the first public unveiling of Facebook’s new mission.

Zuckerberg is doing exactly what Kotter recommends: “Executives who communicate well incorporate messages into their hour-by-hour activities…using all existing communication channels to broadcast the vision.”

Average leaders who see change coming will set a new course to navigate the change. But great leaders rally teams to embrace the new course, and they do so by communicating a clear and concise vision — early, often and consistently.

Read article on Forbes.com