By Steve Daly
April 02, 1993 at 05:00 AM EST

Film-appreciation classes crammed onto silver platters: That’s what ”special-edition” laserdiscs used to be, when they first appeared in the mid-’80s. Exploiting laser technology’s ability to offer still-frame archives and alternate audio tracks, a small company called Voyager introduced annotated versions of classics (like Citizen Kane) and cult favorites (like Blade Runner) with a tone that was always serious and scholarly. Lately, though, special-edition discs from a wide range of companies are dropping the pointer and going show-biz. Why? Because movie studios and directors have come to see deluxe laser editions as promotional tools.

Consider the monumentally self-congratulatory disc edition of Rambling Rose (1991). Open the box, and there’s a Hallmark-style booklet containing fancily typeset raves from mostly no-name critics (typical blurb: ”The most moving American film so far!”). This is a sweet movie, with wonderful performances by Diane Ladd and Robert Duvall as Southern parents, and Laura Dern as the ”oversexed” teen they take into their home. But it’s a modest bud, and even its staunchest fans might wilt after rambling through more than three hours of extra audio and visual material presented by director Martha Coolidge.

Not that Coolidge doesn’t make an engaging host. On alternate audio tracks, she provides often insightful commentary about the performances, and introduces several cut scenes and a making-of featurette in chats that have her speaking into the camera. But what audience is Coolidge really addressing? She spells out production minutiae in such detail (such as how a kitchen set was designed to accommodate camera moves) that the program plays more like a training film than like a keepsake. In fact, the whole package resembles an audiovisual resume, complete with on-screen letters from the producer, composer, cinematographer, production designer, and costumer, all singing Coolidge’s and one another’s praises.

There’s just as much sheer hype on Disney’s disc-only ”Exclusive Archive Collection” editions of 20,000 Leagues Under the Sea (1954) and Mary Poppins (1964). Each package is billed as a ”glimpse into the magical Disney creative process,” as if these movies were the product of corporate pixie dust. They treat the steps of film production like points on a theme-park ride, passing through briskly and leaving much unexplained. Split screens compare storyboards with final scenes but don’t examine the reasons for changes. And, while it’s wonderful to see sketches for, say, an unfilmed zoo scene from Poppins, couldn’t we be told what was supposed to happen in it? Plus: Exactly what made the studio cut a creepy, ocean-depths animated segment from 20,000 Leagues, dredged up here with much ado?

To be fair, the Disney discs do offer thumbnail production histories in their liner notes. But the behind-the-scenes chapters on the discs themselves rarely address who contributed what. Of course, that’s probably how Uncle Walt would have wanted it. Never one to dilute the Disney brand name with long credit lists, Walt always commanded center stage as the impresario behind his movies. Direct and unfiltered, that’s how these discs present him: He’s shown lording over Poppins‘ opening night in a you-are-there short and plugging 20,000 Leagues on his ’50s TV program.

However entertaining these segments are, they’re propaganda, not scholarship. Sadly, the special-edition laserdisc that takes a genuinely historical view may itself soon be history. (Grades are for these laser editions, not for the films themselves.) Rambling Rose: C 20,000 Leagues Under the Sea: C+ Mary Poppins: C