Finding–and holding onto–today’s preschool audience is tough, but netting those viewers with educon is even tougher. Yet curriculum-based Sesame Street has topped the preschool heap for more than three decades (staunchly remaining one of the top 10 series with kids ages two to five), providing a permanent programming address for PBS Kids.

‘Sesame Street literally defined the PBS Kids brand when it launched 33 years ago,’ muses PBS senior VP and co-chief program executive John Wilson. ‘It really took kids programming to a place it hadn’t been before.’ A Sesame Workshop production, the series debuted on PBS in 1969 with a US$7-million annual operating budget, and has built its reputation upon a chameleon-like ability to evolve and blend with the changing needs and environments of its target demo. Now a veritable mega-brand with a yearly budget of US$120 million, Sesame Street keeps its finger on the preschool pulse and celebrates its 4000th episode this month by welcoming a new wave of change to its programming neighborhood.

‘The changes we made this season are the most dramatic we’ve ever made,’ says executive producer Michael Loman. They’re also intended to appeal to the smallest of Sesame Street viewers. Originally targeted to kids ages three to five, annual brand tracking studies found that the show’s audience base has shifted largely towards the younger end of that demo: kids ages two and three. ‘That poses a new problem,’ says Loman. ‘How do you reach a younger audience and make sure it’s benefiting them educationally without lowering the show’s standards?’

The solution lay in format changes. The first 45 minutes of the new show contains a series of predictable segments that appear in the same time slot each day, much like the structured activity of day care. New segments include ‘The Monster Clubhouse’ (a Marx Brothers-esque physical comedy segment that invites children to become part of a Monster Club meeting); ‘Hero Guy’ (an animated superhero alter-ego created by Baby Bear); ‘The Count’s Number of the Day;’ ‘Spanish Word of the Day’ and ‘Cookie’s Letter of the Day.’

The live-action street story has also undergone a format shift. In the past, the story was split up into five or six segments, interspersed with animation and other sequences. Now, in response to research indicating that younger kids have longer attention spans, the street story runs as one continuous scene. Loman explains: ‘Initially, Sesame Street was modeled on 1960s series Laugh-In, with little vignettes interspersed throughout. Now children are used to longer story lines on television and home videos. In testing, we found that it was even more effective to have the story line run together.’

Since kids are also more aware of the world around them, the new season incorporates subject matter based on recent world events, including those of September 11. Child psychologists came up with four subject areas–fear, inclusion, loss and bullying–to help answer children’s questions in the aftermath of the tragedy. The 33rd season opened with an ep that teaches kids how to deal with fear: after Elmo is traumatized by a fire at Mr. Hooper’s store, he and Maria go to a real fire department to learn about what firefighters do.

Despite so much structural upheaval, the segment hosted by Elmo remains unchanged–thanks in part to its warm reception by viewers and its heavy focus on interactivity. ‘Elmo’s World,’ first added to the Sesame Street lineup in the 30th season, rounds out the final 15 minutes of each hour-long episode in season 33.