A current self-examination undertaken by the nation's newspapers could lead to a new era of "exploratory journalism," one moving away from a "throwing rocks at authority" role that has characterized some reporting in recent years, a leading editor said yesterday.

Eugene Patterson, president and editor of the St. petersburg Times, told the American Society of Newspaper Editors convention here that advocacy journalism in the last decade "made a sturdier press and a stronger society," following a period during which the press generally was "obedient" and respectful of authority.

But there now is need for a "new dimension," one which adds "better of reporting of issues . . . to our investigative approach," said Patterson, outgoing president of the society.

Patterson also told the ASNE meeting, in its second day, that the organization had launched a "new activism" in the past year to enlarge its concerns on ethics, minority hiring, newspaper writing and research about readership.

On minority hiring, a society committee reported yesterday that there has "been a significant but nowhere near sufficient increase" in the number of minorities employed in the nation's newsrooms.

The committee said:

Two-thirds of U.S. newspapers have no minority employes. Overall, newspapers employ 1,700 minority persons (62 percent of them blacks), or 4 percent of the newsroom population.

While the number of minority reporters is increasing, the number of editors is "still pitifully small," making them "underrepresented when decisions are made" on where stories

The editors also were told yesterday that they have presented a misleading picture of American life by overlooking some changes in the country's mood and exaggerating others.

The editors were scolded, gently on some points and harshly on others, by five panelists who were asked to discuss the question, "What the hell is going on in this country?" The answer, the editors were told, cannot be discerned by reading the daily newspapers.

As proof, the Rev. Andrew Greeley, a sociologist at the University of Chicago, offered some "noncontroversial statements" about America today, including the observations that Americans' confidence in their institutions has been slipping, that opposition to school busing reflects racial prejudice, and that Catholics are the most likely American group to oppose abortion.

"Few of those who pontificate about the mood of America would seriously question" those assertions, Greeley said. "But all the propositions I have cited are false."

Michael Myers, the assistant director of the National Association for the Advancement of Colored People, discussed newspapers' treatment of race relations.

"Editors decide what the news is," Myers said, in a voice etched with quiet rage. "I must say to you . . . blacks are apparently no longer news. The agenda of equality is no longer considered as newsworthy as the agenda of whites who beat back blacks."