Considering that Wikipedia has reached Top Five world status among Web sites – with more than 330 million users – its annual Wikimania conference, which ended Friday night in Buenos Aires, featured a lot of hand-wringing about all the problems the project faces.

After emerging on the scene less than a decade ago, Wikipedia is facing a slowdown in growth. Why? Are new contributors being scared away? Are there too many rules? Why are the biggest players in the community overwhelmingly men? And white? And will Wikipedia ever become a true global phenomenon, as relevant to the lives of people in the third world as it is in the developed world?

Like a freelancer suddenly overwhelmed with assignments, Wikipedians often found themselves looking back at the sleepy days when they were largely left alone. Scratch that. Maybe the better comparison is to the successful journalists who look back to the time when they were so busy they never had time to reflect.

One of the focal points for these questions was a talk by Andrew Lih, author of “The Wikipedia Revolution,” on Wikipedia’s demographic decline and its implications for “an emergent community.”

“Why now?” he asked. “Because we now have statistics,” was his answer. For years, he said, there was so much information about all the changes to Wikipedia articles that it could not be collected, let alone analyzed. Not any more.

Mr. Lih, who is a professor at the University of Southern California’s journalism school, shared his talk with Erick Zachte, the Wikimedia Foundation’s data analyst. The two proceeded to offer various plots for how the English Wikipedia story could end.

“We had been saying the sky’s the limit – infinite growth,” Mr. Lih said. “That’s kind of silly.”

Other projected growth patterns, such as no more new articles in a matter of years, he concluded, also may be too severe.

One thing was sure about English-language Wikipedia, he said: the summer of 2007 was its high point in growth in articles and contributors.

After running through a range of projections, including something called the Gartner Hype Cycle , he then offered his own hypothesis. Growth of English-language Wikipedia would be slowing sharply over the next few years. He made an analogy to an orchard. There were the articles that were like fruit on the ground (say, “apple” or “Africa”) that were tackled early in the project. Slightly more specialized articles quickly followed (so-called “low-hanging fruit”). Finally there are the fruit at the top of the trees, which, after three million articles, are also largely in the bushel basket.

What looked like sharp growth at the start was really Wikipedia collecting all that material, he said. It couldn’t last. Growth will come from specialized articles, maintenance and news, both events and ideas and products. “Human knowledge is always expanding, but not at the same steep rate,” he said.

The question, he said, was how English Wikipedia dealt with these new circumstances. It could be, he and others observed, that rules and advice have proliferated as much as the articles without the same benefits. That as the project matures, it is harder for newcomers to join.

The old methods may no longer be the best. “What works for a hamlet or village may not work for a metropolis,” he said.

While Mr. Lih questioned what lack of growth in contributors and articles says about the long-term viability of the project, Matthew Curinga, a doctoral candidate in the program in Communication, Computing, and Technology in Education at Columbia University, asked what these changes mean for Wikipedia’s vision of “radical equality.”

Looking at the writings of the philosopher Jacques Rancière, Mr. Curinga spoke about how Wikipedia takes concrete steps to “institute equality.” It’s not simply that anyone is allowed to edit articles, he said, but there are tabs that invite anyone who shows up to edit — its motto is “the encyclopedia anyone can edit.”

Recent changes focused on improving the quality may work against equality, he said. “Bots,” programs that make changes on a mass scale, are not accessible to all, since they require programming skills. As articles include complex tables, people are discouraged from making changes.

And then there are the rules and bureaucracy.“What would happen,” he asked a room of about 20 people, “if there were no administrators or bureaucrats? Would Wikipedia collapse?”

“I think most people think it is important that it be a fine encyclopedia, with high-quality articles,” he said. But, he asked, “would we be willing to live with a little less successful encyclopedia for more freedom?”

At Mr. Lih’s numbers-heavy talk, one woman stood up and said she answered mail to Wikipedia and was struck that people “have an emotional connection to Wikipedia – we need to sustain it and reproduce it.”

“Why don’t women feel comfortable to contribute?” she asked.

Could it be, she asked in Spanish-accented English, “less women is connected to the fact we are very cold and not as emotionally connected?”

Everyone agreed she had a good point and moved on to the next question.