CARL ANDRE IS DOOMED to a life of explaining exactly what his sculpture is not. His bold experiments in Minimalism, subjects of a retrospective at the Institute for Contemporary Art, fall victim to misinterpretation by two camps of museum-goers.

Those who profess sophisticated knowledge of art try to read symbolic meaning into his forms, seeing them as conceptual statements. Others take one look at the sculptures--mass-produced chunks of wood, bricks and steel plates arrayed in monumental checkerboards and rough-hewn pyramids--and decide this is not "art" at all, but something the fabled 5-year-old could do.

If forced to choose, Andre would side with the latter group, rejoicing in the directness of a child's expression. Andre relates to his creations on an intuitive level. For him, sculpture is meant not to communicate ideas, but to enrich experience. "Nothing but the cheapest and lowest art conveys meaning," he proclaims.

At the same time, Andre recognizes that art is a social process, that "art must be seen and apprehended by someone else." "Seeing" for Andre doesn't stop with giving a sculpture the old once-over-lightly from across the room. He wants people to touch the grain of the wood, step over the bricks, stand on the metal plates, and feel the magnesium up through their shoes.

Andre designs his sculptures to transform the space around them. Since the gallery space is a vital part of the creation, he personally installs all his shows.

At the I.C.A. the results of this deliberation are striking. The two-dimensional floor pieces upstairs succeed in breaking down the separation of art vs. walls-and-floors conspicuous in museum displays. Here the geometric patterns of metal plates meld with the room. Particularly dramatic is "Twelfth Copper Corner," a triangle of 78 copper plates extending from the corner opposite the staircase.

Andre must defend his work against repeated claims that such nonrepresentational and non-sculpted work cannot be called art. Actually, his art is important precisely because it is so radically different from traditional sculpture. Andre seeks to express himself in the simplest, most fundamental manner.

FRANK STELLA INFLUENCED Andre's desire to reduce art to its purest. Andre and Stella both attended Andover, but first met in New York in the '50s. Andre was impressed by Stella's line paintings, in which the painter restricted himself to an extremely limited visual vocabulary.

Andre spent the following years experimenting with different materials and environments in his work. At a gallery in New York he dropped 800 plastic blocks from a canvas bag and, letting gravity arrange them, called it "Spill." For "Joint" he lined up a row of hay bales across a field in Vermont. The timber, granite, and metals now assembled in Boston reflect his childhood years near the shipyards and stone quarries of Quincy, Mass.

Andre's explorations into new realms of sculpture contributed to the evolution of two other schools of art. Environmental artists created "earthworks" inseparable from individual settings. Christo's running fence in California is one of the most famous of these projects.

Another group of artists branched into Conceptual Art, in which simple forms were infused with symbolism. Andre's work is often confused with Conceptual art because the two produce similar visual results. Andre, however, denies that his works are ever conceived with specific ideas in mind and claims that the titles for pieces come merely from his "pleasure in the English language."

Andre's is an art that deserves to be talked about and thought about--but only because we cannot fully experience it in the way Andre hopes. It would never occur to most of us to climb on or crawl under, let alone create, such sculpture. As adults we tend to show interest in something by recognizing the need to "understand" it, to dissect, discuss, define. Unfortunately for Andre, we outgrow the child's ability to appreciate things for what they are.