What a difference a year makes, if you happen to be encountering Robert Altman. Expansive in the summer of 1975, prior to the opening of "Nashville," Altman seemed defensive and despondent in the summer of 1976, shortly after the release of Buffalo Bill and the Indians" and the brooadcasting of his dispute with producer Dino De Laurentiis. De Laurentiis had expressed his dissatisfaction with "Buffalo Bill" by cancelling their highly publicized "three-picture deal," which was to have included an Altman film version of E.L. Doctorow's "Ragime."

It was the expansive, confident Altman, more or less, who held forth at his quarters in the Hotel Delmonico shortly before the New York premiere of his latest feature, "3 Women," which opens this Friday, May 13 (hmmm. . .), at the K-B Cinema.

"You might say I've risen from Dino's ashes," chuckled Altman, assessing the relative changes in fortune that show business may bring in the course of a year. De Laurentiis had fallen considerably short of his desire to surpass the box-office performance of "Jaws" with a remake of "King Kong." The movie version of "Ragtime" still seemed to be awaiting the availability of 1975 Oscar winner Milos Forman, who was supposedly grooming "Hai" for the screen. The trade papers reported that De Laurentiis was eager to reserve the services of John G. Avildsen, the 1976 Oscar-winner, who ended up making a multiple picture deal with Columbia.

Altman had rebounded from twin setbacks, the box-office failure of "Buffalo Bill" and the cancellation of an elaboratore, all-star comedy called "The Y.I.G. Epoxy," based on Robert Grossbach's novel about the staff members of a scientific research institute, "Easy and Hard Ways Out." He arranged to produce two films directed by friends - Robert Benton's "The Late Show" and Alan Rudolph's "Welcome to L.A." - and then set up a picture of his own, "3 Women," after literally dreaming the premise and securing financial backing from 20th Century-Fox on the strength of a 30-page story outline.

"The Late Show" had become the first critical and box-office success of 1977, a circumstance Altman could barely resist gloating about, since the film's chances had been disparaged by a number of people at Warner Bros., the same company scheduled to make "The Y.I.G. Epoxy," a project that has faded along with the authority of its prospective producer, former record company tycoon David Geffen, a short-lived production supervisor at Warners.

"I kept hearing that 'The Late Show' was unreleasable," Altman said. "Now it's the pride of the studio. A typical reversal. I'm convinced that no movie has to lose money, provided it's handled with a little care. That's one of the reasons I'm glad United Artists agreed to let us distribute 'Welcome to L.A.' ourselves. It's gotten some rough reviews here and there, but we had a good premiere in Seattle, and we're doing business in New York. Bention is coming out toward the end of the year to do a sequel to 'The Late Show.' You hadn't heard? Sure, we'll call it 'The Late, Late Show. I can't think of a reason in the world why we shouldn't. It would be a shame not to get those two characters back together again."

Altman claimed to be in a defensive mood about his own picture, a fascinating, engrossing but ultimately inexplicable fable about personality formation and transference between two abysmally naive young women, played by Shelley Duvall and Sissy Spacek, who meet while working as therapists at a Palm Springs spa for the elderly and become roommates. "I'm tired of talking to people who don't like '3 Women,'" Altman grumbled, mentioning several friends who supposedly didn't like it, including Doctorow, with whom he still plans to collaborate on a movie version of "The Book of Daniel" one of these days.

After a little elaboration, it becomes apparent that none of these friendly critics really disliked "3 Women." They simply had reservations about the way it's resolved, if one can call Altman's murky, enigmatic choice of denoucement a resolutioN. Similar reservations are likely to be felt by most people who see the film, including ardent admirers.

"Doctorow said he was with it up to the hospital scene," Altman remarked. "When the nurse describes Sissy's condition as temporary amnesia, he began to get a little worried and never got over it. He thought that sounded like some soap opera ailment. But it's perfectly legitimate. There shouldn't be anything outrageous about this diagnosis after what's happened to her. You've gotta begin resolving the material in some way, otherwise it's not a story. Yeah, you'd have a relationship, and probably a touching one, but it still wouldn't be a story. The film ends in a way that means something definite to me, but it might not be your interpretation or the next person's. There doesn't have to be one interpretation.

"I think people try too hard to get a single comprehensible meaning out of a film. You don't have to approach it that way. It can be more like a painting. I also think filmmakers try to explain what they're doing too precisely. The worst thing Fellini did was talk about what he intended 'Casanova' to mean in advance. He prepared the way for his own bad reviews.' Although "3 Women" is the first moive Altman has ever constructed from a dream fragment - and he is probably the only American director who could make a feature not only quickly but presentably in this fashion - he said he has "always trusted" the images and intuitions that come to him in dreams. "I don't think I have exceptional recall," Altman said, "but I can usually remember as much as I want to, and I believe the dream state is an invaluable creative resource. In my experience a lot of problems do seem to get solved if you sleep on them. '3 Women' got started when I dreamed about two girls. One begins taking over the personality traits of the other. What does the one who sees her personality being snatched away do about it?

"That was it. Originally, there were only two women, although the title was always going to be '3 Women.' I developed the third woman character, the painter played by the Janice Rule, much later, when I was trying to fill out the conception. What I tried to do was retain the psychological mystery of the personality theft or crisis, or whatever you want to call it, but surround it with very ordinary, tangible details. That's where the girls' jobs and apartment and the desert setting began to come into it. I wanted all those things to be totally realistic and still enhance the mystery."

Speaking of his association with Altman recently, Robert Benton recalled that he was full of misapprehensions about his producer's working methods. "I told him I didn't think I'd be able to improvise," Benton said, "and he was startled. 'I don't improvise,' he said, 'I just rewrite later than you do.'" Altman acknowledged the anecdote. "It's a good line," he said, "and it's also true. I prefer to get up early in the morning to write the final dialogue for that day's scenes. It's not improvisation. It's just a technique for keeping the working process as spontaneous as possible. I like to reserve diagloue rewrites for the morning of shooting. It's a way of forcing myself to get an early, concentrated start on that day's work.

"Anyway, neither Sissy nor Shelley can improvise in the strict sense of the term. They need the lines to speak before the cameras begin turning.They contributed dialogue and shaped their own characters in a lot of ways, but none of it was improvised in front of the camera."

Altman said he was unaware of the acting feat Sissy Spacek had achieved in "Carrie" when he cast her in "3 Women." In fact, he still hasn't seen "Carrie" in English, although he screened a dubbed French version in order to audition the actress who would also be dubbing Spacek's voice for the French version of his own film.

Audience aren't likely to be mystified by Altman's high regard for these young actresses. It's the vision of women that they've been asked to embody that will provoke enduring controversy and confusion. It may or may not help to know that Altman himself grew up in a family dominated by women. "My father was around," he said. "In fact, he's still around. He recently remarried at the age of 80. He just didn't figure in the decision-making process. I was the oldest kid, but the only boy in the familY. I was pretty much surrounded by aunts and sisters and female cousins. Naturally, like every member of a minority group, I think I learned how to get along by becoming watchful and manipulative."

The fatalistic streak in Altman's movies evidently reflects his general view of mankind as a self-deceiving species whose pretensions don't amount to much when stacked up against natural processes and urges. Presumably, this form of ignorance is one of the things he was preoccupied with while constructing "3 Women." The life-just-gones-on motif that permeates his films also permeates his conversation, sometimes in a seductively melancholy way and sometimes in a merely complacent and slightly annoying way.The man and his moives, the artis and his art, are temperamentally, perversely inseparable. Although he works intuitively, Altman also seems to work with more discipline and economy than his contemporaries. By the time he retires he may be the only important American director of his generation with as many titles to his credit as the directors who worked in Hollywood during its heyday. "3 Women" is the 11th feature Altman has completed in the last 7 years, and he has an ambitious new project, "A Wedding," a social comedy designed to reproduce the format of "Nashville" while doubling the number of characters, in preparation for shooting this summer outside Chicago.

He claims it began partly in jest: "While we were on location with '3 Women," I consented to an interview with a girl from some obscure little paper, the Universal Backpack or something. She was nervous and got a little pompous, which caused me to get a little impatient, so when she asked what I planned to do next, I said, 'A wedding. Yeah, I've always wanted to just go out and film a wedding.'

"I was being sarcastic, but when I began to think about it, it didn't seem like such a bad idea. So John Considine and I went to work on a script, which brings about four dozen characters together for a big, splashy wedding ceremony. I realized afterwards that I was looking for a way to put together some of the ingredients that might have gone into 'The Y.I.G. Epoxy.' We planned to deploy a large cast around a gigantic studio set, and it could have been great fun.

"The Y.I.G. Expoxy' never should have fallen apart! Warners had to pay a large settlement to Peter Falk, who had already signed, and I could have forced them to pay up on a signed contract too, if I had thought it was in my interest to insist. David Geffen had never produced a movie before, and he simply panicked. Alan Rudolph and I put together a loose screenplay in about five days, which was sufficient for the time being, and I began assembling the cast. Geffen couldn't believe that everything would work out all right once we got the ingredients together. There was a lot of beating around the bush before it became clear that they wanted us out.

"At first the problem was the so-called Altman stock company. I said I understood and had a lot of people in mind who had never been identified with my films. I even asked if there was anyone in particular they wanted to shy away from. They came up with Joel Grey, who had been in exactly one of my films. So I said, 'Fine, there's no role for Joel in this anyway.'

"Eventually, they got around to saying, 'We don't want this to seem too much like a Robert Altman movie.' At that point I figured it was time to call it a day."