Yes, it's been a record summer at the box office. And 1987 looks to be the film industry's best year ever. But the numbers can be somewhat deceiving. They tell only part of the story.

By Labor Day, summer box-office totals will slightly surpass 1984's standing record of $1.58 billion, says Variety's industry analyst, A.D. Murphy. At this pace, the calendar year 1987 should also break the existing industry high-water mark of $4 billion, also set in 1984. "It's in the bag," Murphy says.

Those figures should be put in perspective, though, since they reflect higher ticket prices, not an increase in the number of tickets sold. Admissions are ahead of last year, but still behind 1984.

The good news is that there were a greater number of box-office successes this summer. "As always, it's a product-driven business," says Barry London, Paramount Pictures' distribution president. "Good movies stimulated people to go out to the movies more often."

So, while the number of tickets sold did not increase, the people who do go to the movies regularly went to see a greater number of films (rather than seeing a blockbuster over and over). The Memorial Day to Labor Day period this year produced only one film that grossed more than $100 million, "Beverly Hills Cop II." The summer of 1984 had three $100 million-plus grossing films ("Indiana Jones and the Temple of Doom," "Ghostbusters" and "Gremlins"). The subsequent two summers had two blockbusters each ("Rambo" and "Back to the Future" both passed $100 million in 1985, as did "Top Gun" and "Karate Kid II" last year).

But there were more films in the middle range -- $40 million to $80 million -- this summer, which is healthier for the industry because the dollars are more evenly distributed among the various studios. The moderate hits included "The Untouchables," "Witches of Eastwick," "Predator," "Dragnet," "The Living Daylights," "Full Metal Jacket," "Robocop," "Snow White and the Seven Dwarfs" and "La Bamba." A late summer entry, "Stakeout," will join the list after Labor Day.

Rarely has the selection of films been so varied. Summer has traditionally been a time for teen comedies and mindless action/adventures (especially sci-fi spectaculars). But there was a much better mix this summer, says Thomas Sherak, 20th Century Fox's marketing/distribution president, due to "a maturation in the movie taste of the American public -- and that includes the kids. Adult-oriented films attracted even younger viewers."

Audiences are getting older, or, more precisely, the population is returning to normal, Murphy explains. The high percentage of teen-agers a few years ago was actually an aberration, he says, reflecting the tail end of the baby boomers, the last of whom will reach 30 by the end of the year. Unlike the members of the preceding generation, those just over 30 still go to the movies in large numbers -- which in part accounts for the increased appetite for more sophisticated films.

The youth market that remains, however, continues to support films such as "Adventures in Babysitting," "Revenge of the Nerds II" and "Spaceballs." Walt Disney Pictures' summer lineup catered almost exclusively to teen-agers, with films such as "Babysitting," "Ernest Goes to Camp" and "Can't Buy Me Love" -- and even preteens with "Benji the Hunted" and "Snow White." For those films, "there's no substitute for summer playing time," says Disney's distribution chief Richard Cook, who keyed most of the studio openings for after June 19 -- after the school year ended.

Cook explains that attendance patterns for summer are different. While movies generally do 75 percent of their business on weekends at other times of year, in summer a full 40 percent to 50 percent of tickets are sold from Monday through Thursday. Out-of-school teens and preteens are the biggest available midweek audience.

But while more sophisticated films such as "The Untouchables" also had youth appeal, teen movies did not cross over to an adult audience. Exceptions were last summer's "Stand By Me" and this year's "La Bamba" and the 50th anniversary release of "Snow White." Otherwise no youth film topped $40 million.

Another reason more movies did business this summer is that more films were released. For the first time in many years virtually all of the major studios are operating at full capacity. Disney, which formerly released only four to six films a year, distributed half a dozen between Memorial Day and Labor Day. Even a mini-major like Orion Pictures had three full-scale summer releases, "The Believers," "Robocop" and "No Way Out."

Another factor that contributed to summer totals is the changing profile of the videocassette market, says Sherak. Industry pundits have long predicted that the popularity of home video would eventually engender more of a taste for movies, and Sherak believes that prognostication has finally become a reality.

At the same time, the boom in the videocassette market is showing signs of peaking. "The novelty of videos has worn off," says London. "It's become more of a hit-driven business. The big video hits like 'Top Gun' and ' "Crocodile" Dundee' were successful as movies first."

Still, the considerable revenue from videocassettes and cable has made more movies profitable, thus freeing up more money to make movies.

But there is a cloud to that silver lining. With an average of four to six movies debuting every weekend over the summer (a pattern that will continue through fall and Christmas), it has become costlier to promote films and to keep them in theaters. Traditionally, studios spend most of their advertising money (between $6 million and $10 million) during the first and third week of a movie's release. First-week dollars go toward helping the movie open strong. The studio then capitalizes on word-of-mouth in the second week and returns for another push during Week 3. Due to the volume of summer releases this year, however, Sherak says it was necessary to spend more on newspaper and TV advertising to keep films from getting lost in the shuffle. And as London points out, "we're not only competing with other movies, but with all the other summer leisure time activities."

For example, "Adventures in Babysitting" failed to score when it opened over the Fourth of July weekend -- the most fiercely competitive summer period. Disney immediately redoubled its efforts to keep the film alive against the following weekend's openings. The strategy worked. Second weekend attendance jumped a remarkable 45 percent. But in the case of Warner Bros.' "Innerspace," which opened the same weekend, additional ad dollars could not revive the film.

As successful as they were, the big summer hits -- from "The Untouchables" to the Steve Martin comedy "Roxanne" -- never reached their maximum profit potential, for no matter how well they performed, after a few weeks theater owners yanked them for newer titles. "In most cases these films were still doing fairly good business," Sherak says. "And if there hadn't been so many new films available, theater owners would have hung on to them."

Another break with summers past was the renewed clout of star power. It's unlikely that a "Witches of Eastwick" would have succeeded without Jack Nicholson and Cher, says producer David Permut. The same applies to his own film "Dragnet," with Dan Aykroyd and Tom Hanks. "Whether the film would have been as big a hit without that cast is questionable," he says. The film attracted an older audience, which remembered the original TV series. But the draw of Aykroyd and Hanks was needed to bring in a large segment of younger viewers. (Permut would not confirm, but both Aykroyd and Hanks have reportedly signed on for "Dragnet II.")

As is true of any film season, there were at least one or "sleepers," good films without star names or easily marketable concepts that manage to captivate audiences and become major hits. Both of this summer's sleepers were musically oriented -- "La Bamba," a biography of '50s rock star Richie Valens, and "Dirty Dancing," a '60s coming-of-age drama featuring a number of dance sequences.

Being a sleeper in such a competitive summer is a true badge of honor. "La Bamba" had a head start, says producer Taylor Hackford. "It was ready last February and we started screening it heavily for college and high school audiences. Columbia did a great marketing job, selling it well to both a mainstream and Hispanic audience." (Valens was Mexican American, and Columbia released the film in both English and Spanish versions.)

In the case of "Dirty Dancing," the odds for failure were greater because the film didn't have the push of a major studio behind it, being the first national release from the film division of Vestron, a home video company. Vestron senior executive William Quigley had originally planned a late-July release, but was scared away by the number of hits still going strong in midsummer. "I used to be a film buyer for the Walter Reade circuit," he says. "By late July, most of the early summer hits are played out. But this year, there were more consistent long-running hits than any summer since 1978."

Unable to secure the theaters he wanted, Quigley pulled the film back to Aug. 21. "Dirty Dancing" made $3.9 million in its opening weekend on fewer than 1,000 screens -- very strong for an independently made film. If it holds up, the $6 million film will make its money back by the end of summer