It's hard to measure laughter and shrieks on a definitive scale, but the children who saw Friday's performance of "In Other Words," a series of skits in mime, song and slapstick in the Kennedy Center's Chatauqua Tent, certainly weren't bored. There is something to be said for actors in leprechaun-like green-knickered suits who come bounding down the aisle and into the audience. Not even "Sesame Street" can match it.

"In Other Words" is really a language lesson made palatable by the energetic antics of Archaesus, an improvisational theater and mime troupe which will perform again this afternoon at 1:30 and 3. Even dull stuff like the alphabet takes on new possibilities if introduced by a story-teller saying, "One day 3 million years ago when the world was just a jungle . . ." while six actors caw and gibber away to indicate that language hasn't been discovered yet.

The children loved it when the "first men" literally band together to outwit the giant mastodon, and when Adolphus Ignatius Fentwhistle, who hates to move, and Sylvia Syllabub, who hates to take, finally learn to communicate with each other.

If the humor is a little blatant and the slapstick a little exaggerated for some adult tastes, the history of speech has rarely been so appealingly presented.