Two of the seven interns who walked off their jobs at the National Endowment for the Humanities Thursday changed their minds yesterday and decided to stay.

Andrea Hinds, 24, and Lydia Barker, 22, decided to keep their jobs as temporary summer clerks in the public affairs office after arriving to sign formal termination papers, according to Endowment personnel director David C. Johnston.

Johnston said that "the two who returned did so, they said, because they needed the jobs."

The seven interns announced Thursday that they would resign, complaining they were victims of reprisals by their boss, Kay Elliott, the public affairs director.

The reason, they said, was that they had leaked to the press the information that Elliott had assigned them, on Endowment time, to help arrange a surprise birthday party for Endowment Chairman Joseph D. Duffey. Duffey has since said he will reimburse the government for such planning costs out of his own pocket.

The interns also complained that their duties had been "abruptly curtailed" and that they were limited to clerical jobs such as clipping newspapers as a result of their role in the newspaper accounts.

On the return of the two intern yesterday, Elliott commented, "Isn't it nice." Asked what duties Hinds and Barker would perform, she said, "Is there's clipping to be done, those clippings will be clipped.

Four interns - Donald Kravet, Susan MacMurdy, Eugene Tarne and Cathy Shumate - submitted signed resignation on Thursday, according to Barbara Benson of the agency's personnel office.

David Braaten, a $130-a-day consultant who also resigned with a blast at Elliott and the Endowment management, did so in a letter to Duffey.

Benson said that Barker, Hinds, and Reed Waller, 22, came to her office yesterday morning to fill out termination papers. Only Waller did after the three were reminded that they were invited to stay on.

Duffey said yesterday that he was "delighted" that the two interns had returned, and repeated that "all the are welcome back."