CAMBRIDGE – In an environment of mobile phones, computers, and Web sites such as MySpace, Facebook, and LinkedIn, it is commonplace to say that we live in a networked world.

But different networks provide new forms of power, and require different styles of leadership. Barack Obama understands this; indeed, it helped to secure his victory.

While Obama was hardly the first American politician to use the Internet, he was the most effective in using new technology to raise money from small donors, energize and coordinate volunteers, and convey his messages directly to voters. Now he is faced with the question of how to use networks to govern.

Networks come in many shapes and sizes. Some create strong ties, while others produce weak ties. Think of the difference between friendships and acquaintances.

Valuable information is more likely to be shared by friends than among acquaintances. But weak ties extend further and provide more novel, innovative, and non-redundant information.

Networks based on strong ties produce the power of loyalty, but may become cliques that re-circulate conventional wisdom. They may succumb to "group think.”

That is why the diversity in Obama’s cabinet choices is important. He has been compared to Abraham Lincoln in his willingness to include rivals as well as friends on his team.

Weak ties, such as one finds on the Internet, are more effective than strong ties for providing the necessary information to link diverse groups together in a cooperative manner.

In other words, weak networks are part of the glue that holds diverse societies together. They are also the basis of democratic leadership. The greatest democratic politicians have a large capacity for shallow friendships.

As leaders increasingly need to understand the relationship of networks to power, they will have to adapt strategies and create teams that benefit from both strong and weak ties. Information creates power, and more people have more information today than at any time in human history.

Technology "democratizes” social and political processes and, for better and worse, institutions play less of a mediating role.

In fact, the basic concept that is sometimes called "Web 2.0” rests on the idea of user-based content bubbling up from below rather than descending from the top of a traditional information hierarchy.

Institutions like Wikipedia and Linux are examples of social production that involve very different roles for leaders than do their traditional counterparts, Encyclopedia Britannica and Microsoft.

Now governments are experimenting with similar means to create and distribute information, but they still have a long way to go.

Governments have traditionally been very hierarchical, but the information revolution is affecting the structure of organizations.

Hierarchies are becoming flatter and embedded in fluid networks of contacts. White-collar knowledge workers respond to different incentives and political appeals than do blue-collar industrial workers.

Polls show that people today are less deferential to authority in organizations and politics.

In business, too, networks are becoming more important. In some cases, one can orchestrate a complex network simply with carefully specified contracts. But the friction of normal life usually creates ambiguities that cannot be fully met in advance.

In describing the success of the Toyota and Linux networks, the Boston Consulting Group concludes that the hard power of monetary carrots and accountability sticks motivates people to perform narrow, specified tasks, but that the soft power of admiration and applause are far more effective stimulants of extraordinary behavior.

Traditional business leadership styles have become less effective. According to Sam Palmisano, the CEO of IBM, hierarchical, command-and-control approaches simply do not work anymore.

They impede information flows inside companies, hampering the fluid and collaborative nature of work today. A study of a major "bricks and clicks” company (one that combines offline and online operations) found that distributed leadership was essential.

In the Internet environment, the traditional view of a leader being decisively in control is difficult to reconcile with reality.

Instead, effective leadership depends on the use of multiple leaders for capable decision-making. Harvard Business School professor John Quelch writes that "business success increasingly depends on the subtleties of soft power.”

Former President George W. Bush called himself "the decider,” but leadership today is more collaborative and integrative than that implies.

One management expert summarizes recent studies as describing an increase in the use of more participative processes.

In other words, the Internet age requires new styles of leadership in which attractive soft power must supplement the traditional hard power of command.

In a networked world, leadership is more like being in the middle of the circle and attracting others than being "king of the mountain” and issuing orders to subordinates down below.

Barack Obama understands this networked dimension of leadership and the importance of the soft power of attraction. Not only did he successfully use networks in his campaign; he has continued to use the Internet to reach out to citizens. 

He has supplemented his major television and radio speeches with Internet-based video clips on YouTube, and his political style has been marked by reaching out in a bipartisan fashion to broad circles of political leaders.

While it is still too early in his presidency to judge the outcome, it is clear that he is attempting to change processes and adapt leadership to a more networked world.

Joseph S. Nye, Jr. is a professor at Harvard’s Kennedy School and author of The Powers to Lead.