EARLIER THIS MONTH, WNEV-TV, channel 7 in Boston began featuring a new anchor team on its 6 p.m. and 11 p.m. newscasts. Tom Ellis, who'd been the long-time anchor of WCVB-TV, channel 5, and Robin Young, who'd spent the last few years in glamorous New York and Los Angeles, were signed on to boost the station's perennially sagging ratings.

Both have received considerable media hype. Both are blow-dried, attractive rising stars with six-figure salaries. Both have appeared on Boston TV before. The new razzle-dazzle duo should boost ratings for a while, perhaps even enough to challenge channel 5--Ellis's old employer--for top spot in the ratings battle.

But if the channel 7 management were to consider the advice of Walter Cronkite and Dan Rather, two old pros who know something about the TV news business, they might have shaken up their newscast in an entirely different manner. The two veterans would believe the station's cosmetic cure-all is the wrong way to remedy an ailing local news show.

Rather disparages "quick fixes" like the theft of Ellis from channel 5. His 1977 book, The Camera Never Blinks, acknowledges that for many stations, "If your ratings are low, (you) just go across town and hire the other station's anchorman." He strongly opposes this ploy, saying "the feeling is that what counts is what is on the marquee, not the integrity of your news," and argues that, in the long run, superficial facelifts do little to boost ratings.

For WNEV, though, mere line-up shuffles (instead of more substantive changes) are something of a tradition. Years ago, the station, then called WNAC-TV, swiped veteran anchor John Henning away from (you guessed it) channel 5. Channel 7's ratings were low when Henning arrived, and they were still low when he was eased out early this year.

In effect, channel 7 has told the viewers, "the only difference between our news operation and channel 5's is John Henning. Since we've hired him, its time for you to switch to us." Clearly, the viewers weren't convinced. They didn't flock to channel 7 either a few months, when it lured two attractive young anchors, Brad Holbrook and Susan Brady, from Nevada and Buffalo respectively.

WHAT WENT WRONG? Despite the dazzling array of outside talent that channel 7 imported, it couldn't win the audience's favor. The hiring of Ellis and Young probably won't fare any better over time. The public wants more.

What should our ambitious TV executives do? For starters, the channel 7 brass could heed the advice of Walter Cronkite, who in his 20 years as anchor of the CBS Evening News came to symbolize integrity in reporting as well as high ratings. In 1976, at a CBS affiliates conference, Cronkite laid out his plans for building a successful local news operation.

He began by asking the local news executives, "Isn't there a homeowner, a longtime resident or at least a young man or woman who has chosen your community and wants to make a career there--isn't he or she likely to give a great deal more integrity and dedication and interest--qualities I might point out, that are easily detectable across the airwaves--than the wanderer looking for the next big break in the next bigger town?"

"And if you don't have those people immediately available, have you thought about raiding your local newspaper? For what you pay those inexperienced announcers, you could hire the best--the best--newspaperman in your town as on-air broadcaster, or news director, or both: a fellow or gal who knows the city like a book, likes the city, warts and all, and plans to raise a family there." But won't viewers turn away from ordinary-looking anchormen? No, says Uncle Walter. Of even a rumpled, pot-bellied greying anchorman, he says, "I'll guarantee you this: he knows more about your town and what makes it tick than ever will be learned by some young fellow from 500 or 1000 or 2000 miles away that some consultant tells you got good ratings there." In fact, he says, "That slightly tousled codger is going to exude more believability and integrity from the nail on the finger of his left hand than that pompadours, pampered announcer is ever going to muster. And isn't that what our news departments are all about, isn't that what you really want to sell: authority, believability, credibility and integrity?"

If Cronkite seems emotional about this topic, he has reason to be. Many media experts, including colleague Rather, worry that a Cronkite--no Redford even in his younger days--would never be given a chance by today's news directors. Viewers didn't turn off Cronkite because he wasn't attractive enough, yet many present-day news directors seem oddly convinced that they would today. It's a mystery why they continue to ignore the lessons of the past and to ascribe to viewers such superficial values. Who says news-watchers are looking for "beautiful people" as anchormen?

Cronkite can't understand it. He guesses that approximately half of these glittery anchormen move--or are booted--to a new city every two years. That's no way to build a loyal, consistent viewership.

IF ANY STATION should heed these lessons, it's channel 7. Viewer rejection of the channel, even with the popular John Henning (who's now anchoring channel four, by the way) suggests not so much a rejection of Henning as the news operation itself. Perhaps the viewers simply didn't feel channel 7 was doing a credible job of reporting the news. Perhaps instead of bringing in high-priced anchor talent, a handful of skilled reporters could have been hired to improving much more of the news operation.

Channel 7 isn't the only station to be duped in hiring big-name free agents. In New York, the ABC affiliate, despite its number one rating, is dumping its two anchors in favor of snazzy Tom Snyder. The two departing anchors, Roseanne Scamardella and Ernie Anastos, are homegrown reporters, with strong local support. So rather than being dazzled by the coming of Snyder, New York viewers have inundated the station with calls of protest, and some emotional viewers have even picketed outside the station.

Boston viewers may respond in the same way. But the Hub may never get the chance to protest the firing of a dependable local newscaster on channel 7. It's hard even to remember the last one.