TV violence: less but still too much

Violence isn't ''in'' this year on television, thank goodness. New shows in the TV season just begun run largely to comedies and spinoffs of Dallas, neither of which is very original nor challenging to the viewer.

Unfortunately violence does continue to exist on the tube. Either after school or in the early evening the unsupervised youngster still can find such objectionable shows as Hawaii Five-O on UHF stations across the land. And a few violent shows are back for another dreary year on network television. Thus although the pattern is significantly better, too much violence remains.

The television industry operates in cycles. In its earliest days it emphasized variety shows, with one station copying another's success. This copycat trend has continued ever since, including Westerns, medical settings, and shows which glorified violence and crime.

The nefarious effects of violence on children have been widely reported. Last year the National Institute on Mental Health released results of a 10-year study on the effects of TV viewing; it found ''overwhelming'' evidence that violence on TV results in violence by children and teens.

As a current example, the most-discussed TV program by youngsters at one day-care center is the crash-filled Dukes of Hazzard, which the boys copy by sending toy cars hurtling through the room. Such TV shows present an unrealistic and exceptionally dangerous misconception of driving. At the same center some children also strike and slap one another in imitation of violent episodes on other shows.

The old argument that such programs are designed for adult viewers is inadequate, since many young children watch television until 10 or 11 at night. Neither sponsors nor station executives do the public a service by supporting violent shows. Now that the networks, at least, perceive that viewers are tired of electronic violence, the amount of it on the airways can be expected to diminish further - the sooner the better.

Even as the TV violence problem apparently is diminishing, a new challenge is rising in the Saturday morning cartoons watched almost exclusively by children. That is the establishing of programs which are based on commercial products for children, and which in part are clearly designed to sell those products. Fifteen years ago child advocates were protesting the existence of effective and sometimes misleading advertisements on Saturday morning; now their concern is that the programs themselves have become advertisements. Included are such shows as PAC-MAN, Rubik the Amazing Cube, and Dungeons & Dragons. Adults would have the sophistication to snap off the set if such a blatant hard-sell for a product came on, but children do not.

There should be a clear distinction between the program and the advertisement , as there is in a newspaper between news story and ad.

Unless stopped, this cynical sales pitch is likely to be the next significant controversy in children's TV programming.