More whimsical nostalgia than probing documentary, PBS' Pioneers of Television is nevertheless a solid and entertaining introduction to some of TV's earliest trailblazers. It doesn't shed any light on its parade of luminaries, but boob-tube buffs are bound to enjoy the feast of archival footage and modern-day interviews.

Pioneers suffers from two misguided directions. First and foremost, its four sections -- Late Night, Sitcoms, Variety and Game Shows -- treat their subject matter with blind reverence. Every TV pioneer spotlighted is cause for praise and celebration, an approach that leaves precious little room for insight.

What the documentary series lacks in analysis is made up in volume. But Pioneers of Television is similarly hampered by its considerable ambitions. Each episode crams in a slew of TV stars, especially the installment on sitcoms, with the net result being a bland superficiality. Perhaps a better approach would have been four episodes devoted to sitcoms alone, or two episodes on variety shows, or .... you get the idea. Directors Steve Boettcher; Mike Trinklein and Jack Jones are the guys at the buffet line with eyes too big for their stomachs.

Tributes of this kind lend themselves to argument over what was left out, of course. I find it a little strange that Tony Orlando and Dawn are hailed as pioneers of the variety show, while Norman Lear is nowhere to be seen in the piece on sitcoms. Oh, well. If there is one thing Pioneers of Television doesn't necessarily lack, it is comprehensiveness.

Late Night (55:35) centers on the three icons of The Tonight Show: Steve Allen, Jack Paar and Johnny Carson. It's the most focused of the episodes, afforded a bit more room to explore what made the talk-show hosts so unique (Allen was the intellectual, Paar the consummate interviewer, Carson the all-around master).

The piece also contains lots of wonderful and rare footage, particularly a mighty-young Johnny hosting a local Los Angeles program called Carson's Cellar. Unfortunately, some clips are slightly compromised because Tonight guests of yesteryear are not identified. (Note to documentarians: We old farts will recognize Sixties-era George Carlin and Flip Wilson, but not so for many viewers under the age of 40).

In addition, Late Night offers some side excursions with other TV talk-show hosts such as Merv Griffin, Joey Bishop and Dick Cavett. It's a kick to hear secret White House tapes of Richard Nixon and aide H.R. Haldeman fulminating against Cavett for interviewing a young antiwar Vietnam veteran named John Kerry.

Interviewees include Cavett, Sigourney Weaver (whose late father was NBC president Pat Weaver), Jay Leno, Regis Philbin, Andy Williams, Hugh Downs, Jonathan Winters, Arsenio Hall, Phyllis Diller, Doc Severinsen, Ed McMahon and Florence Henderson. The episode also features the last interview with Merv Griffin before his death in August, 2007.

Sitcoms (55:35) touches on five bona fide classics: The Honeymooners, I Love Lucy, Make Room for Daddy, The Andy Griffith Show and The Dick Van Dyke Show. That should make for fun viewing, but Sitcoms is the weakest of the lot, full of fawning praise and cliché-laden voiceover narration. Despite an abundance of interviews -- including Van Dyke, Griffith, Mary Tyler Moore, Jim Nabors, Marlo Thomas and Rose Marie -- there's not much meat to chew on. Its saving grace is rare archival footage, such as Dick Van Dyke Show creator Carl Reiner starring in an early incarnation of the series.

Variety (55:38) is a vast improvement, memorializing a genre that effectively went extinct sometime in the Seventies. There's a lot of ground to cover here, but Pioneers of Television manages to hit the touchstones: Milton Berle, Ed Sullivan, Your Show of Shows, Red Skelton, Rowan & Martin's Laugh-In, Carol Burnett and Flip Wilson are a few of the highlights.

The clips make for great fun. Ed Sullivan appears in all his awkward, and oddly endearing, splendor. Arthur Godfrey ridicules a sponsor's canned chicken soup for skimping on the chicken, while Pat Paulsen of The Smothers Brothers Comedy Hour reminds us that subversive political humor on TV has been around a lot longer than The Daily Show. Interviewees include: Sid Caesar, Phyllis Diller, Tim Conway, Vicki Lawrence, Andy Williams, Tommy Smothers, Jerry Stiller, Jonathan Winters, Dick Van Dyke and Pat Harrington.

Of the four episodes, Game Shows (55:36) is easily the most interesting. Not coincidentally, it's also the most offbeat, zeroing in on a slice of TV programming that often doesn't get the respect it deserves. Best of all, the doc is loaded with vintage clips from some great old shows, including Password, Jeopardy, What's My Line?, You Bet Your Life, 21, This Is Your Life, Let's Make a Deal, Truth or Consequences and Hollywood Squares.

Still, the narrative is as slim as the series' other parts, with the producers shoehorning in a litany of names: Mark Goodson, Ralph Edwards, Merv Griffin, Chuck Barris, Bill Cullen and so on. The name-checking, while not exactly edifying, is more than made up for by the archival footage and nifty anecdotes courtesy the interviewees: Bob Barker, Merv Griffin, Wink Martindale, Bob Eubanks, Monty Hall, Tom Kennedy, Peter Marshall, Chuck Woolery, Jack Narz and game-show producer Bob Stewart.

Its four sections can only be played separately. That's just as well, considering that four-hours-plus might be a bit exhausting over a single viewing.

Presented in anamorphic widescreen and with a 1.78:1 aspect ratio, Pioneers of Television is loaded with archival TV footage that veers wildly in terms of picture quality. That's to be expected, and it doesn't detract from viewers' enjoyment.

The Dolby Digital 2.0 isn't showy, but it gets the job done without any discernible distortion or drop-out.

The only extra are 15 minutes of extended interviews with "the pioneers." Those featured are Merv Griffin, Betty White, Tim Conway, Florence Henderson, Phyllis Diller, Dick Cavett and Jonathan Winters.

Short on insight but long on great vintage footage, Pioneers of Television is a valentine to some of TV's greatest stars of yesteryear. While the narration is clichéd and some pioneers inevitably receive short shrift, the clips are fun and memorable. And seriously, in these sorts of enterprises, isn't a trip down memory lane really what you're expecting?