How can I not write about the flap over Katy Perry on "Sesame Street"? That story has everything: a scantily clad pop star; charges of exposing children to untoward, even libidinous displays; egregiously bad acting; woolly, pint-size sock puppets. Katy Perry poked fun at the controversy during an appearance on "Saturday Night Live" Sept. 25. Early last week "Sesame Street" posted teaser videos from its upcoming season, including a segment pairing the ever-popular Elmo with the singer and occasional firebrand Katy Perry. In this particular clip, Perry bemoans — in song — the fact that Elmo doesn't want to play dress-up with her. It's bouncy and moderately cute and probably not annoying to children. This is all well and good, but some parents commented upon the singer's choice of attire for the performance: a low-cut yellow-green number that leaves, as they say, little to the imagination. One or another of the media outlets picked up on the story and a mini-controversy was born. "Sesame Street" was quick to respond. The segment would remain on YouTube and KatyPerry.com, the show said, but in light of the feedback would be dropped from the broadcast version of the program. I would like to say that if any aspect of the video deserves censure it's the song itself: a reworked version of Perry's 2008 hit "Hot N Cold." But you know what, I actually kind of like it. Really, if I have any complaint about the clip it's neither the clothes nor the song but rather this: it fails to instruct children about science. Elmo doesn't want to play dress-up with Katy Perry. Parents wish Perry would dress up a little more. Last November, as part of the White House's "Educate to Innovate" campaign, "Sesame Street" announced a two-year initiative seeking to teach kids about science, technology, education and math, or STEM. First Lady Michelle Obama helped to kick off the initiative — and the 40th anniversary of the show — with a segment on the natural world. The initiative continues this year, with 13 episodes focusing on the process of scientific investigation — encouraging kids to ask questions, experiment, observe and report. Using this four-step process, children will examine thunderstorms, gravity, wind, rocks and camouflage. Maybe the Katy Perry appearance isn't a missed opportunity, though. While it doesn't directly address any of the above topics, commentators — including an assortment of cynical blogger types — suggest that it might help to draw a bigger crowd for episodes that do: children's fathers, for example. The show itself hinted at this in a statement about the video: "'Sesame Street' has always been written on two levels, for the child and adult," it read. "We use parodies and celebrity segments to interest adults in the show because we know that a child learns best when co-viewing with a parent or caregiver."