Classical ballet is something of a hothouse flower, not the sort of thing kids are likely to pick up on the street or the playground. In order to spark a child's (or even an adult's) interest in such a traditionally elitist and "feminine" art form, crucial connections must be made between concert dance and familiar everyday activities.

Arthur Mitchell and his wonderful Dance Theatre of Harlem know just how to get those connections across. The company's "Arts Exposure" program yesterday, part of the Kennedy Center's continuing Imagination Celebration, pointed out basic similarities between ballet and basketball, ballet and disco, ballet and cats, ballet and almost anything involving strong legs, flexible knees and utmost control.

Mitchell, a warm, fast-talking man with a Cheshire cat smile, began with a mini-history of ballet. Though his use of sophisticated terminology floored several of the adults present, the kids drank it all in. And when the dancers came on to demonstrate barrework, dazzling lifts and sections from such works as "Holberg Suite," Troy Games" and the psychedelic "Phythmatron," the young ones' enthusiasm could scarcely be contained.

One little girl watched the ballerinas execute their rondes de jambe , then circled her leg in imitation. A group of fans left their seats to lean against the stage for a closer look.

Perhaps the most inspirational moment came after Mitchell had coaxed a motley crew of volunteers onstage to demonostrate current dance crazes. One tiny lad, shyly swaying amidst his more uninhibited peers, noticed Mitchell leaping back and forth, and suddenly followed suit. The crowd cheered.