PBS recently debuted its newest science series for preschoolers, The Cat in the Hat Knows a Lot About That! Children’s television may be educational in many ways, but can it really teach kids science? Research on how children learn provides a useful guide for determining whether this show and others are worth watching.

Because preschoolers have a limited capacity for processing information, they are more likely to comprehend educational content that links directly into a narrative, says Shalom Fisch of MediaKidz Research & Consulting. In that way, the plot and the lesson do not compete for cognitive resources. Cat accomplishes this goal well by, for example, teaching kids about twigs, mud and grass through a plot about saving a baby bird.

Other shows support preschoolers’ learning by accounting for their attention spans and modeling behaviors for them to emulate. After demonstrating a scientific concept, such as how shadows work, Peep and the Big Wide World (WGBH) depicts youngsters experimenting with that concept—say, by making shadow puppets. The show models curiosity and exploration for kids while narrator Joan Cusack offers wry observations aimed at adults. This kind of grown-up appeal is a nice bonus because research suggests that when parents join their children in active TV viewing, kids understand more of what they see.

Dinosaur Train (PBS) focuses on laying the groundwork for good reasoning skills. Each episode begins with an introduction like “Today we’re going to visit the Triceratops and find out what they eat!” which helps kids focus their attention where it is needed. Then the characters deduce, for example, what kinds of food different dinosaurs eat by examining their mouths and teeth. This offers a template on which kids can base their own critical thinking.

Go, Diego, Go! (Nickelodeon), a cartoon whose young narrator helps animals in danger, takes a more interactive approach, asking viewers direct questions and leaving enough time for them to process and shout answers. Being asked to participate might help motivate learning or even promote a sense of mastery, which is of tremendous value to children.