The finding that children spend longer watching television and playing online than they do at school is one that gets less shocking the more you think about it.

Proper outrage in this case requires two heroic assumptions. The first is that all that time at school is spent productively. This is evidently not true. A great deal of time at school is spent not doing very much at all. And that is just the lessons, as yesterday's report on the boredom of four and five-year-olds at school shows. There are plenty of other school-related but non-educational activities, such as travelling, that take up more time than the daily literacy hour.

The second assumption is that the time children spend watching television or using computers is time wasted. Of course there are programmes, games and websites that are undesirable. That is the time to turn the television off, to hide the mouse, to disable the wireless connection, to set up a password. But there is much to learn from good children's television, of which there is plenty. The treasure trove of sites connected to learning establishments, museums and encyclopedias brings within the grasp of all children information that once would have demanded a trip to the library, a distant continent or another age.

There is nothing intrinsically wrong with looking at screens. The best cartoons are wonderful, not because they teach us anything, though they do, but because they are entertaining. The same is true of the best computer games - intricate, extraordinary worlds created not just to watch, but to inhabit. They are fun. Anxious parents, if they had a go, might even agree.