The eagerly awaited move spectacle "Close Encounters of the Third Kind," which director Steven Spielberg prefers to describe as "an advanture in science speculation" about the UFO phenomenon, appears to have passed its first crucial tests of credibility. Following two previews Sunday at the Ziegfeld Theater, apprehensive reviewers and theater owners, who comprised a large percentage of the audience, felt considerably relieved.

There seemed to be general agreement that while "Close Encounters" might not surpass the box-office records established by "Star Wars" and Speilberg's own "Jaws," it will still quite an attraction, destined to end up among the top moneymakers of modern film history.

"Close Encounters" is a more exciting and ingratiating set of variations on the mystical science-fiction theme introduced in [WORD ILLEGIBLE] A certain amount of apprehension about the film had been created when Columbia, the American distributor, canceled a mammoth press preview, originally scheduled for Los Angeles on Oct. 24. A week later the publication of an unfavorable advance report in New York magazine under the byline of William Flanagan, a financial writer who succeeded in crashing a sneak preview in Dallas, sent Columbia sock reeling.

A favorable advance review appeared the same day in Time magazine, but the bad news had a more immediate impact. The stock dropped three points - from 19 to 16 - before rallying to 18 by the end of the week. Planagan's prediction that the movie would be "a colossal flop" seemed to be addressed more to the investment community than to the movie-going public, which will ultimately determine how much of a success "Close Encounters" becomes.

One publicist connected with the movie bemoaned the fact that she hadn't been invited to Dallas."Even if I couldn't have seen the movie," she said, "I do know Flanagan, and I could have kept him out." Everyone connected with the movie claims to be mystified at how Time critics also managed to see the film.

At a press conference yesterday at the Americana Hotel, Spielberg said he was upset by both the New York and Time articles. "The Dallas preview was intended to give me an opportunity to test the film," he said. "I think the press should wait to review the finished film. 'Close Encounters' has gone through an amazing transformation from rough cut tot he present version. Changes were made on the basis of the Dallas showing. Seven or eight minutes went out, and some new shots were inserted. For example, I shot a whole new sequence of the head of an extraterrestrial emerging from its spaceship when the original sequence didn't get a whisper of reaction from the audience."

The press conference was also attended by special effects superior Douglas Trumbull, technical adviser Dr. J. Allen Hynek, producers Michael Phillips and Julia Phillips, actresses Terl Garr and Mclinda Dillon and 5-year-old Cary Guffey, a little boy from Georgia cast as Dillon's son, who is briefly abducted by a UFO.

The session began inauspiciously, suggesting an exercise in close platitudes of the silliest kind.

Michael Phillips looked deep into Spielberg's eyes and said, "I'd just like to tell Steve how much I admire him." Commenting on the most spectacular special effects in the picture, the climactic appearance of the extraterrestrials' super space-transport. Mclinda Dillon said, "I think when I saw the Mother Ship, for the first time I saw God."

It felt to Spielberg, Trumbull and Hynek to try to keep the film's achievements in proportion. According to Hynek, "Anyone conversant with UFO phenomena will know Steve did his homework very well. The general impression will be that this is science fiction, but it is not. All the sightings and ocurrences depicted in the film have been reported."

Trumbull allowed that creating the stuperdous Mother Ship was very much like trying to visualize God. I'm particularly proud of the affects because we succeeded in creating the sort of nebulosity and lumination Dr. Hynek gave to us as real data. We wanted to get away from the Star Wars' effects, which were wonderful examples of hard-edged space hardware.

"'Close Encounters' was a far more difficult problem than [WORD ILLEGIBLE] at this time. The facts that effects had to be created and juxtaposed with reality posed many problems, and I [WORD ILLEGIBLE] they were the most difficult technological problems I'll ever have to cope with. Steve is a taskmaster and demanded the highest levels of illusion we were capable of."

Asked if the film was a remake of "Firelight," an 8mm, movie he shot in his [WORD ILLEGIBLE] the 23-year-old Spielberg replied: "No, it's a sequal. 'Firelight' was [WORD ILLEGIBLE] hours long[WORD ILLEGIBLE] strange lights in the sky, and much more hard-core [WORD ILLEGIBLE] because from those lights came things with jaws that ate people. I wasn't thinking of being deliberately [WORD ILLEGBLE] when I conceived 'Close Encounters,' but this was not going to be a movie where the people would be consumed and digested. I think we have an advanced technology of our own to be proud of even though it may be encountering an even more advanced technology."

Asked to confirm the report that he and George Lukes had exchanged profit participations in their new films. Spielberg said, "George and I did some swapping on couple of years ago. It was in between friends and George had made me very rich so far. I think George may be forming his own studio up in New York, Calif. What's probably going to happen is that [WORDS ILLEGIBEL] him. [LINE ILLEGIBLE]

President Jimmy Carter's report of a UFO sighting when he was governor of Georgia enjoys a place of prominence in the movie's publicity material. Spielberg amplified by saying, "I'm sure the President will see the film; he's a filmgoer and he did have a UFO experience in 1969. One of his campaign promises was that he'd get right to the quick of the UFO story. That's a promise we're all very interested in seeing him keep."

According to producer Michael Phillips, the film cost approximately $19 million to shoot and has an advertising budget of "in the neighborhood of" $7 to $8 million. He said that product tie-ins would be "quite extensive - everything ranging from toys and T-shirts to perfume." A reporter asked how a "Close Encounters" perfume would be differentiated from the competition. "It will lead to close encounters of the best kind," offered Dr. Hynek. Spielberg promptly went him one better. "When you score," he said, "It's a close encounter of the third kind."