As the fall elections approach, voters seem reluctant to move in any clear direction. There is widespread dissatisfaction with President Reagan, but there is no clear move to the Democrats. In many ways, this just reflects the continuing decline in party affiliation and traditional coalitions.

There are many reasons for this, of course, but one important reason is the presence in the electorate of millions of people whose political views are not adequately reflected by either party. Politicians and political analysts continue to use a single liberal-conservative dimension to analyze the ideological views of the American people, even as that approach is increasingly seen to be flawed.

In our own studies, we have gone beyond the liberal-conservative dimension. Using the 1976 Center for Political Studies Election Survey, we separated the question of government intervention in the economy from the question of civil liberties.

Combining these two major issue dimensions gives us four different ideological categories. The liberal generally supports civil liberties and expanded government intervention into the economy. The opposite position -- opposing government economic intervention and civil liberties -- is taken by the conservative. The populist, while sharing the conservative's opposition to expanded civil liberties, supports intervention in the economy. Finally, the libertarian supports expansion of civil liberties and opposes government intervention in the economy.

We found that 73 percent of the survey sample could be classified as consistent or nearly consistent in one of these four categories. The populist group is the largest with 24 percent of the sample; 18 percent could be characterized as conservatives, 16 percent liberals, and 13 percent libertarians, according to our analysis.

It should be especially noted that while 34 percent of the respondents can be reasonably classified as liberal or conservative, 37 percent fall into the populist or libertarian category.

Among the oldest group -- people who matured during the Depression -- the predominant categories are populist and conservative, reflecting a division over economic issues but a not civil liberties.

People who matured during the '50s -- often characterized as the period of "the end of ideology" -- are evenly divided among all four categories. The next group, who matured during the heady days of John F. Kennedy and Camelot, are heavily liberal.

The youngest group in this survey reached political maturity in the '70s, the era of Vietnam, Watergate and a general disillusionment with government. In this age group the two largest categories are liberal and libertarian, reflecting a complete reversal from the oldest group; the division is still over economic issues, but people of this age group heavily support civil liberties.

We see similar differences when we look at the income and education categories. The populist group virtually preempts the other ideologies in the lowest income category and is barely found in the highest income group. The libertarian category -- people who oppose government involvement in either economic or personal activities -- is the largest for the two highest income groups, representing over 30 percent of the respondents in the $25,000 income and over group.

Similarly, populists are the largest group among those with a grade-school or high-school education and are almost nonexistent at higher education levels. The proportions of liberals and libertarians increase significantly with higher levels of education.

The increasing incidence of split-ticket voting, dissatisfaction with political parties, and non-voting may well be related to the presence of two ideological groups in society whose belief systems are not reflected by the Democratic or the Republican party or by their candidates.

Although the populists are the larger of the two "new" ideological groups, their potential influence is minimized by the fact that they come disproportionately from social groups not usually very active in American politics. (The New Right, however, has had some success mobilizing opposition to some of the advances in individual liberties issues, such as abortion.) Libertarians, on the other hand, tend to be well-educated and of higher income and thus more likely to be active and influential in politics. Furthermore, the younger age groups have higher proportions of libertarians.

It seems likely that a large proportion of our libertarian voters chose President Reagan in the 1980 election, being willing to overlook his individual liberties positions because they liked his stand on economic issues. But with high levels of spending and deficits continuing and the administration stepping up its support for school prayer and anti-abortion legislation, Reagan and the Republicans may find libertarians looking around for an alternative.