A nonpartisan voting research group will issue a pre-election warning that a "nontraditional candidate" with an "activist organization" could win most of the presidential primaries and force himself on the party convention.

This conclusion is based on a computerized study by the Voters Caucus, a task force of University of Utah professors with backgrounds in computer science, political science and voter surveys. "Low voter turnout presents real possibilities to the lesser-known, lesser-liked and lesser-followed candidates," the study said.

Marion G. (Pat) Robertson and Jesse L. Jackson, for example, could run away with the presidential primaries because of their "organizational capacity and the high motivation of their supporters," the study suggests. Robertson could win the GOP nomination, and Democratic front-runner Jackson could grab his party's nomination by sweeping the primaries. Yet, neither has a national following greater than 15 percent of the electorate.

Here is the startling arithmetic the professors compiled for the Voters Caucus: Only 19 percent of the nation's eligible voters turned out for the last presidential primaries. In the New York primary, for example, only 10.4 percent bothered to vote. Walter F. Mondale won that state's Democratic primary with just 4.7 percent of the eligible vote.

It took less than 6.8 percent of the eligible voters to win the average primary in 1984. Because of this low turnout, Jackson was able to mobilize enough dedicated followers to make a respectable showing and establish himself as a power to be reckoned with. He stunned party leaders by winning the Louisiana primary with a scant 4.3 percent of the eligible voters.

Sources close to Jackson say he never expected to win the nomination in 1984. His strategy, they say, was to establish himself as the preeminent black leader. But he now has an excellent chance of winning many of the 1988 Democratic primaries.

It would follow that he should then receive the Democratic presidential nomination. But the unspoken truth is that his nomination might alienate enough white votes to lose the general election for the Democrats. On the other hand, if the party denies Jackson the nomination, it could antagonize enough black voters to lose the election.

The latest Gallup Poll shows Vice President George Bush as the favorite of 47 percent of Republican voters, with Sen. Robert J. Dole (Kan.) second with 22 percent. Robertson has only 7 percent. But these voters, fired with the evangelical spirit, are the most likely to show up at the polls. If it takes only 6.8 percent to win a primary, Robertson could defeat his more popular rivals.

Concluded the Voters Caucus: "If the United States is to have leadership, both qualified and representative of its citizens, then a majority of the American people must take their citizenship responsibilities seriously."

Footnote: The Voters Caucus is a nonpartisan, volunteer organization, sponsored by the International Platform Association, a group of public speakers. It distributes voter information to a grass-roots network of political columnists and broadcasters. Jack Anderson is the nonpaid president of the International Platform Association.