On “Sesame Street,” a distressed cow has a big problem. She made it up the stairs to the beauty parlor but now, her bouffant piled high, she’s stuck. Cows can go up stairs, she moans, but not down.

Enter Super Grover 2.0. Out from his bottomless “utility sock” comes an enormous ramp, which, as the cow cheerily notes before clomping on down, is “a sloping surface that goes from high to low.”

Simple ABCs and 123s? So old school. In the last four years, “Sesame Street” has set itself a much larger goal: teaching nature, math, science and engineering concepts and problem-solving to a preschool audience — with topics like how a pulley works or how to go about investigating what’s making Mr. Snuffleupagus sneeze.

The content is wrapped in the traditional silliness; these are still Muppets. But the more sophisticated programming, on a show that frequently draws an audience even younger than the 3- to-5-year-olds it targets, raises a question: Is there any evidence that it is doing anything more than making PBS and parents feel good?