Some commentators, among them Nicolai Ouroussoff, the architecture critic of The New York Times, have asserted that the Modern's architecture and design department gradually lost steam under Mr. Riley's long tenure.  Mr. Bergdoll declined to specify what exhibitions he might be contemplating, beyond saying that he hoped to include the work of some lesser-known architects. "It's an interesting moment to try to step back and see if one can do something in the context of MoMA that reflects the architecture profession more widely, and not just a handful of stars," he said.  Beyond individual architects, "there are more burning issues," he said, adding, "The really interesting questions have much more to do with architectural process and other kinds of trends and phenomena that are happening in the design world."  To those who debate whether architecture and design should continue to be commingled in one department at the Modern, Mr. Bergdoll's reply is that the fusion makes sense. For one thing, he said, the advent of digital fabrication has blurred the boundaries. "It's a historic moment," he said. "It would be a mistake to pull the two apart. I hope we can do shows that will suggest that might not be the right question — that architecture and design are on a continuum."  Mr. Bergdoll said he hoped to study the collection in greater depth and add to it. "There are things historically that the museum hasn't collected, the most famous being Art Deco," he said. "That was part of the museum's missionary zeal against American mainstream taste in the 1930's. I'm not sure that's a position the museum shouldn't fundamentally rethink."  Mr. Bergdoll is not new to MoMA. He collaborated with Mr. Riley on "Mies in Berlin," a 2001 show on Mies van der Rohe's early decades that also traveled to Berlin, Barcelona and London. He has served for three years on the museum's art and design committee, which advises the board on acquisitions and exhibitions.  Mr. Bergdoll is also an expert on Marcel Breuer, who designed the Whitney Museum of American Art, and he organized "Breuer in Minnesota" at the Minneapolis Institute of Arts in 2002. He is now at work on a book about Breuer that is to be published by Phaidon Press in London.  Reared in a Philadelphia suburb, Mr. Bergdoll earned bachelor's and Ph.D. degrees at Columbia and bachelor's and master's degrees at Kings College, Cambridge, in England.  He joined the Columbia art history and archaeology faculty in 1985 and became department chairman in 2004. He helped establish the university's art history program in Paris and worked with the Graduate School of Architecture to create a Ph.D. program in architectural history there as well.  He said he planned to continue developing seminar classes at Columbia over the next two years.  Among other works, Mr. Bergdoll has written well-received monographs on the Prussian architect Karl Friedrich Schinkel and the French 19th-century architect Léon Vaudoyer.  Founded in 1932 by the architect Philip Johnson, the Modern's architecture and design department molded the nation's conversation about the field for decades. The job of chief curator is named for Johnson, and Mr. Bergdoll acknowledged that it might be natural to feel intimidated by that legacy.  But he said it was potentially liberating to be the first appointed since Johnson's death, last year.  "I will essentially be the first person who is after the close of that period," Mr. Bergdoll said. "It's a moment when a whole group of people can form a new configuration. I think there's a lot to invent."  A version of this article appears in print on , on Page E1 of the New York edition with the headline: The Modern Announces New Architecture Curator. Order Reprints| Today's Paper|Subscribe
Barry Bergdoll, a prominent scholar of 19th- and 20th-century architecture, follows Terence Riley, who last November signaled his intention to resign after 14 years in the post.