When a play's cast of characters includes "an ancient hag, a pair of idiots, a deformed young man, a stammerer, a spasmodic adolescent," not to mention Henry James, his sister Alice and P.T. Barnum, there has to be an unusual mind sitting behind the typewriter.

Actually, Joan Schenkar does not sit behind a typewriter until the final draft -- she prints her first efforts by hand directly after rising at 5 a.m., in order to capture the ideas and images provided by her dreams. Needless to say, her plays are not in any traditional form, but are what she calls "experimental theater."

"I think naturalism is the death of American theater," she said during a recent visit to Washington for the premiere of one of her plays, "Signs of Life," by the Horizons Theatre. "I'd hate to say I have plots . . . Life does not present resolutions, everything all neatly tied up by the end of the third act. So naturalism is artificial in that sense. Experimental theater is more faithful to the interior life of humans . . . My plays make people nervous because they leave without resolutions, and they laugh at things they think they shouldn't be laughing at."

Schenkar is a small woman with curly black hair that on this day is decorated with a red rosette attached to a headband. She clearly has a restless intelligence and a probing mind and was originally surprised to find that her intended Ph.D. thesis on Henry James turned into a play. (The thesis never got finished. "Thank God, otherwise I might have to be teaching college somewhere.") She lives in Long Island City, N.Y. ("It's wonderful -- a little town where the Mafia used to stash their mothers"), and came down to see the play because she thought it would be fun "to see Washington without tear gas."

She measures her career as a playwright in notebooks -- each contains about one year's work, and she is now on her seventh. "Signs of Life" was written several notebooks ago, in 1979. Her next play is called "Between the Acts" and is due to be produced in London soon. It is set in a garden, and the weather and the flowers are characters. Another play, "Last of Hitler," is set as a post-World War II radio serial starring the Fu hrer and Eva Braun, who have escaped from the bunker and are living in a Jewish retirement community in Florida. "It's really about anti-Semitism," Schenkar said. For the production at the Theatre for the New City in New York, the entire theater was converted into a large 1940s radio.

Her plays are meant to be played "like Noel Coward," without the "horrible tendency to play the subtext." The scripts contain detailed notes as to what should be happening when and how (for example: "The scene should induce . . . a sharp feeling of disappointment"). She rejects the idea that this specificity is at odds with "experimental theater," which is not, she said, "sloppy or vague."

Her writing is preceded by considerable research, which is then filtered through her dreams. For "Signs of Life" she fashioned one character -- her favorite -- on the founder of American gynecology, J. Marion Sims, who invented the "uterine guillotine." He also, she said, performed an operation on a woman for entertainment at his daughter's wedding, and called himself "the architect of the vagina."

For her next play, "Big Bad Brain," she learned three computer languages and "hung out with computer nerds," whom she found to be "pseudo-macho febrile young men." In case you're wondering, she is rabidly anticomputer -- "I would die before I would use a word processor," she said flatly -- and the play is a cautionary tale.

"I think it changes writing," she elaborated. "For example, I recently bought myself a present of all 13 volumes of the Oxford English Dictionary. Did you know they are going to put it all on a floppy disc? That will eliminate the pleasure of what you find on your way to something else! A computer does not allow for accidents . . . A lot of it is incredibly onanistic. It is all about putting your feelings and processes outside the body . . . My writing comes from a very deep level, and a word processor forces you to focus in a completely different way. To me it's like the difference between water-skiing and deep-sea diving . . . There should be a way to make the computer expand the language rather than contract it."

After being derailed from her academic life, Schenkar plunged into the creative world. For a time she lived on a farm in Vermont, given to her by her father, who was hoping it would get her out of New York's Chelsea Hotel. It did, and in the process she learned carpentry, electrical work and agriculture. "If Mr. Reagan pushes that button I'll be one of those out there helping to build shelters," she said. She lives now in an apartment filled with toys (she bought a train set to help her with one script) and the eight musical instruments she plays, and drifts off to her important dreamland in a lavish, white Victorian bedroom. She likes to ride a bike around New York "because it's so dangerous."

Schenkar teaches "creative writing for performance art" at the School for the Visual Arts in New York, which she describes as "incredibly kinky." The job doesn't pay much, but it offers a pool of students to help on her productions and "a very good Xerox machine."

"Theater should be about the things that are too frightening to be lived in real life," Schenkar said. "You know what one of my next projects is? I want to do an evening of three one-acts grouped under the title, 'Nothing Is Funnier Than Death.' "