Mr. Reside also emphasized the library’s material on various theater technicians, many of whom remain unlisted on Wikipedia, or whose entries are brief.

He pointed specifically to the designer Boris Aronson, who created pioneering scenes, costumes, lighting and sets for dozens of Broadway shows but whose Wikipedia entry seems unjustly anemic. The library has Mr. Aronson’s papers, which were donated by his wife in 1987 and include designs, programs, scripts and production materials.

The partnership is intended to benefit both Wikipedia and the library. Ben Vershbow, the manager of NYPL Labs, the library’s research and development unit, acknowledged “a relatively recent history of suspicion and antagonism” between libraries and open-source Internet databases, but he said he believed that relationship had healed. “We’re training our staff to learn best practices of Wikipedia, to add links and content, in appropriate ways, to articles which correspond with their areas of expertise,” he said.

Those links, which appear as references at the bottom of an entry, can be valuable. “We’ve found that we get a good amount of traffic from Wikipedia articles where someone has taken the time to add an appropriate link out to a primary resource that we have,” Mr. Vershbow said. “Some people talk about search engine optimization — making sure that your Web content is well-formed and can be found easily — but Wikipedia is its own discovery mechanism.”

Richard Knipel, president of the Wikimedia New York City chapter and an organizer of Saturday’s event, is an editor and writer for the site; his user name, Pharos, refers to the Pharos of Alexandria, one of the seven wonders of the ancient world. Mr. Knipel said that Wikipedia “improves with your understanding of it,” adding: “As you understand its structure and the way it’s created, you can get more value out of it. That’s part of what we want to teach in libraries — how to get the most from a Wikipedia article, and how to contribute the most to a Wikipedia article.”