No one spoke the word “crowdsourcing.” But that was the theme of a presentation Thursday evening by “Frontline” producer Rachel Dretzin, whose next documentary, “Digital Nation,” will be a collaborative effort between her team and visitors to the “Digital Nation” Web site. “Digital Nation” is an attempt to explain how our dependence on — and obsession with — the Internet is changing our culture for better and for worse.

Dretzin is putting all of her footage and interviews online. There’s a blog tracking progress of the documentary. A series of interactive chats is under way. And folks are encouraged to submit their own video and audio commentaries about the good, the bad and the ugly aspects of online existence. There’s even a recommended “Digital Nation” hashtag (#dig_nat) for Twitter users.

“There is absolutely no way to be an expert. This is all of our story,” said Dretzin in an appearance at WGBH-TV (Channel 2), where “Frontline” is based. (Disclosure: I am a paid contributor to another WGBH program, “Beat the Press.”)

The idea, she added, is that rather than making the film in isolation and then getting reaction from the audience, the reaction would come first, followed by the documentary, which will come out sometime in 2010. “It’s an experiment for all of us,” she said.

Dretzin’s last “Frontline” film was 2008’s “Growing Up Online.” As was the case with that film, the author Douglas Rushkoff will be the on-camera correspondent in “Digital Nation.”

Collaborative journalism that combines the efforts of professionals and amateurs — sometimes called “crowdsourcing” — is one of the more promising developments to arise from Internet-based news ventures. New York University journalism professor Jay Rosen, a leading new-media thinker, refers to such amateurs as “the people formerly known as the audience.”

The challenge for Dretzin is to integrate what the former audience has to say into her film, rather than merely featuring it as an online adjunct.