ACCORDING TO THE research professionals, whose work in such matters is respected as revealed truth by the television network titans, the Sunday Baltimore debate attracted a viewing audience of approximately 50 million Americans. In a presidential election thst is expected to draw about 80 million registered voters to the polls, any campaign event that draws this kind of crowd and attenttion is, by definition and arithmetic, significant.

It is tribute of sorts to both seemed very much themselves in the League of Women Voters debate Sunday night. Undoubtedly both candidates, and their partisans, were disappointed with some aspect of an answer. But neither man need be at all discouraged about his overall performance. Each did on Sunday night what he does well. Mr. Anderson was brimming with facts and figures. Mr. Reagan sounded the themes that have ben his throughout this campaign year. Both men were faithful to their messages. Those "surprise" junkies who populate the political scene at once proclaimed the exchange a bore and a disappointment because of the lack of anything New. But the fact is that most of the 50 million people who were watching had never had the chance to here either Mr. Anderson or Mr. Reagan give his uninterrupted (and unedited) views on so many issues. And none had been able to watch both men do so under the intense and immense pressure of a general election president debate.

Mr. Anderson and Mr. Reagan do enjoy some recent debating advantage over the missing President Carter. For Ronald Reagan, Baltimore represented the sixth televised candidates' debate he has participated in this year. (President Carter, of course, has yet to debate any of his primary or general election opponents.)

Statisticians tell us that we can assume, if he is receiving 15 percent of the national vote, that John Anderson had the support of approximately 7 1/2 million people in the Sunday night television audience. If Gov. Reagan and President Carter are both drawing the support of 40 percent, then each man had 20 million viewers supporting him.Another 2 1/2 million viewers were undecided voters.

Frankly, it is difficult to see how, based upon anything we saw in Baltimore, the absent Mr. Carter could have picked up any sizable support from the evening. Almost certainly, Mr. Reagan and Mr. Anderson left with more votes than each came in with. For example, if only one out of four viewers (which seems low) was impressed by John Anderson, his 7 1/2 million had grown to 12 1/2 million by 11 p.m. and, in spite of all the criticism about its not being a debate and so forth, the evening probably did help a lot of voters to answer what has to be one of the most important and confusing questions about the men who would be present: What kind of a guy is he anyway? What is he like?

It is a modest claim, but it seems likely that because of Sunday night in Baltimore, people do have a little better idea of what kind of guys Ronald Reagan and John Anderson are and a little better perspective on what kind of president each would be starting next Jan. 20.