PBS’ “The Pioneers of Television” returns for a fourth season, offering more fuzzy nostalgia, and squandered opportunity. While it’s something of a kick to celebrate programs from TV’s past, the franchise suffers from its pigheaded refusal to incorporate voices beyond the actual stars it features, providing a once-over-lightly account that could easily be enriched by incorporating a few behind-the-scenes and third-party voices. As is, a show that provides understandable and welcome comfort food for public TV’s older audience serves up a much thinner gruel than it ought to have been.

The latest batch of four episodes begins with “Standup to Sitcom,” featuring comics who successfully made the transition to TV, including Jerry Seinfeld, Tim Allen, Roseanne, Ray Romano, Bob Newhart and Bill Cosby. On its face, so far, so good.

Yet those performers are the only ones, for the most part, enlisted to share their memories, even when their anecdotes directly reference others who were involved in the process. Romano, for example, recalls how “Everybody Loves Raymond” showrunner Phil Rosenthal urged him to kiss Peter Boyle on the head during a scene, a flourish the comic resisted. Yet the story would benefit from hearing the producer’s version of why he knew the moment would pay off, as Romano now acknowledges.

In that respect, “Pioneers of Television” often provides less than half the story, and in some instances, that’s enough. It’s interesting hearing Seinfeld talk about how standup and scripted TV are so mismatched – the most creatively isolated medium, he notes, versus the most collaborative – or Allen and Romano discuss how they were paired up with acting teachers when they made the leap.

Still, even then, there’s no reference of the fallout from their success – how the enormous popularity of comedian-driven sitcoms produced a wave of copycats and imitators, only to see most of those who came after the “Pioneers” wind up getting their wagons ransacked.

Additional installments in the four-episode run are “Doctors & Nurses,” “Breaking Barriers” and “Acting Funny.”

Given TV’s relentless pursuit of younger demos, it’s hard not to think well of anything that has the temerity to put the word “Pioneers” in the title. That said, any display of respect for the medium’s elders worthy of its spurs would by rights include more depth than this.

TV Review: ‘Pioneers of Television’

(Documentary series; PBS, Tue. April 15, 8 p.m.)

  • Production: Produced by Boettcher Trinklein.
  • Crew: Executive producers, Steve Boettcher, Mike Trinklein. 60 MIN.
  • Cast: Narrator: Benjamin Bratt. With: Tim Allen, Bob Newhart, Roseanne, Ray Romano, Jerry Seinfeld
  • Music By: