Shocked at the support shown for a controversial conservative caucus in the Presbyterian Church (U.S.A.), a denominational panel conducting hearings on the group's activities has decided to commission a scientific survey.

The panel is exploring the church's relationship to the conservative Presbyterian Lay Committee. It hopes the survey is completed in time for its next meeting, Nov. 8 to 10 in Phoenix.

After yet another outpouring of support for the Lay Committee at hearings Sept. 14 and 15 in Chicago, the Rev. James V. Johnson of Columbus, Ga., chairman of the panel, questioned whether Lay Committee support is as strong as hearings and letters to the committee suggest.

"Intuitively we do not believe that the Presbyterian Lay Committee is as popular as what we have heard and read would indicate," he said. "We need some means to get a broader sampling of opinion from throughout the church."

In an interview this week, Johnson said the committee decided to commission the survey after all but one of 20 speakers at the Chicago hearing voiced strong support for the Lay Committee, repeating the lopsided support shown at other regional hearings in the last year.

In addition to the support voiced at the hearings, the panel has been inundated with thousands of letters of support generated through appeals issued in the Lay Committee's monthly publication, The Presbyterian Layman.

Johnson's panel is preparing a report on the relationship between the church and the Lay Committee for presentation to the denomination's 1991 General Assembly.

In recent years the Lay Committee has infuriated the Presbyterian hierarchy through the constant barrage of criticism it has hurled at church leaders in the pages of the Layman.

One of the most highly charged allegations was made in the Layman's September-October 1989 issue, when the paper accused a high-ranking church missions official of being used by North Korean communists. More recently, in its May-June 1990 edition, the publication accused church staff members in Nicaragua of actively campaigning during elections there for ousted leftist President Daniel Ortega.

At the Chicago meeting, Johnson's panel formulated 16 questions that will constitute the body of the scientific survey.

The Rev. Robert Campbell, president of the Lay Committee, said Sept. 25 that he has no problems with plans to conduct the survey and expressed confidence that it will confirm widespread support for the Lay Committee in the 2.9 million-member denomination.

Campbell said the Lay Committee has never asked people to appear on its behalf at any of the hearings. He suggested that attendance at those hearings can be attributed largely to publicity generated through official church channels, noting, "The church has done a better job than we have of publicizing them."

Johnson said he expects the surveys to reveal a more balanced opinion of the Lay Committee in the church at large. However, he added that "we may be surprised . . . . We have no hard data, and that's what we're looking for."