Michael Asher, the conceptual artist who challenged expectations of what constitutes a work of art and what happens during an art critique, died Oct. 15 at his home in Los Angeles. He was 69.

His death was confirmed by his assistant, Yoko Kanayama. No cause of death was reported.

A teacher at the California Institute of the Arts since 1973, Mr. Asher was famous for his wit and candor — and marathon-style “crits,” or critiques, that left vivid memories with generations of students. Designed to review student work, these courses could by his own account run from 10 a.m. to midnight.

His art projects are called in art-world jargon “institutional critique”: work that somehow analyzes or questions the particular conditions of a museum or gallery environment.

Unlike the work of some other artists grouped under that umbrella, Mr. Asher’s was not fueled by political dogma as much as intelligence and curiosity: How will an art experience change if you alter a choice operating assumption, often in the form of an architectural element?

One early “intervention,” as this breed of artwork is known, was a 1970 piece at Pomona College that involved removing the gallery doors, essentially forcing the gallery to stay open all day and night instead of the usual, restricted hours.

He reprised the concept of keeping a museum open 24-7 recently, both in his contribution for the 2010 Whitney Biennial (for which he won the Bucksbaum Award, given to one artist in the show) and in his work for the 2011 Pacific Standard Time show at the Pomona College Museum of Art.

For another early work, in 1974, he turned his attention to the Claire Copley gallery in Los Angeles. There he removed a crucial wall that protected the office space from view, framing the art gallery’s behind-the-scenes business operations as something worth viewing itself.

“Michael devoted his work to exploring the limits of the galleries and schools and museums that give context and space for art, poking at all sorts of barriers and shibboleths with a humor that was sometimes sly, and sometimes hilarious,” Thomas Lawson, art school dean at the California Institute of the Arts, wrote in an online tribute. “He removed walls and doors and windows from galleries and museum spaces, letting in daylight and air, letting out preconceptions.”

John Baldessari, the conceptual artist who brought Mr. Asher onto the faculty of CalArts, calls his work “slyly subversive — he loved interrupting people’s normal way of understanding the world. I can imagine Michael doing a work where the hot water comes out of the cold water faucet and the cold comes out of the hot.”

In 1979, Mr. Asher set his sights on an artwork at the Art Institute of Chicago: a 20th-century reproduction of a marble sculpture by the 18th-century French sculptor Jean-Antoine Houdon that stood for decades on the steps of the museum. He moved it into an 18th-century paintings gallery where a real Houdon might be found, in what critics describe as an exposéof the museum’s hierarchies of value.

In 2005 Mr. Asher took the same reproduction, which had been shipped off to Chicago City Hall, and moved it back to an 18th-century gallery, highlighting the ways the museum itself had changed in the interim.

Mr. Asher also over the years received awards and distinctions, including a Guggenheim Fellowship and National Endowment for the Arts grants.

But his work, not designed for an object-obsessed market, never brought him commercial success. Most of the work wasn’t even designed to last. As Los Angeles Times art critic Christopher Knight once wrote: “Asher doesn’t merely grant privilege to the art idea over the art object. Instead, he embraces experience as fundamental to a meaningful work of art.”

Michael Max Asher was born in Los Angeles on July 15, 1943. He received a bachelor’s degree in fine arts from the University of California at Irvine in 1966. His parents were Leonard Asher, a physician, and Betty Asher, who originally worked as a nurse.

Over time his mother developed an interest in contemporary art. She worked as an assistant to Los Angeles County Museum of Art curator Maurice Tuchman, helped to raise funds for the museum and ultimately ran a gallery in partnership with Patricia Faure. The gallery showed work by such artists as Michael McMillen, Joel Shapiro, Kenneth Noland and Sam Francis.

Mr. Asher had no immediate survivors.

— Los Angeles Times