NEW YORK — Tablet computers are so easy to use that even a 3-year-old can master them.

And that has some pediatricians and other health experts worried.

Since navigating a tablet generally doesn’t require the ability to type or read, children as young as toddlers can quickly learn how to stream movies, scroll through family photos or play simple games.

That ease-of-use makes tablets -and smartphones- popular with busy parents who use them to pacify their kids during car rides, restaurant outings or while they’re at home trying to get dinner on the table. And many feel a little less guilty about it if they think there’s educational value to the apps and games their children use.

The devices are expected to rank among the top holiday gifts for children this year. Gadget makers such as Samsung have introduced tablets specifically designed for kids and many manufacturers of adult tablets now include parental controls. Those products are in addition to the slew of kiddie tablets produced by electronic toy makers such as LeapFrog, Vtech and Toys R Us.

But some experts note there’s no evidence that screen time – whether from a TV or tablet – provides any educational or developmental benefits for babies and […]