"The Zing Sha Slithery Shy Hag's Old Magic Shadow Show" was the name given to last night's presentation by the Ririe-Woodbury Dance Company (from Salt Lake City) at the Kennedy Center's Theater Lab. The program, which will have a repeat public performance Saturday morning, is part of the Center's fifth annual Imagination Celebration, a national children's arts festival. The show is exactly like the title in all respects, good and bad -- it's a blend of fantasy and whimsy; it sports a profusion of outlandish effects; it goes on much too long without adding to comprehension or pleasure; and it's rather too much of a precious muchness.

"Zing Sha," for short, is conspicuously a "multimedia" effort, clearly derived from the work of Alwin Nikolais, that wizard of illusion, and also harking back in some respects to the original mistress of light-cum-fabric displays, Loie Fuller. It is almost superabundantly inclusive: Slide projections, color transforms, silhouettings, prop like inflated pillows and magic lanterns, fairy-tale costumes and headgear, spacey electronic sound, echo effects, voice-over and live dialogue and dance idioms ranging from ballet, acrobatics, modern, mime, "ethnic" and Pilobolus-like body linkages all come into play.

The one unifying element is the figure of the Shy Hag, a doggerel-spouting sorceress who conjures up a succession of motley, unconnected charades. The adult performers and assisting children are reasonably skilled and lively, though the whole thing falls apart at the end with a gauche attempt at audience involvement.

The show has its quotient of charm and spirit, mostly on the visual side: Lorrie Sue Keller, who conceived, wrote, designed and helped choreograph it, has a plastic-arts background. One would think, though, that the last thing needed by a generation reared on space shots, computer toys and kidvid is saccharine and unbridled gimmickry. Children of the '80s know all there is to know about imagination running riot. What they might find novel and revelatory is a demonstration of the power of selectivity, order and subtlety -- in other words, a lesson in the difference between art and indulgent reverie. One has only to think of the music J.S. Bach composed for the delight and edification of his numerous offspring to know how much can be accomplished along these lines without exceeding the capacities of the young.