A group of students trying to organize a chapter of the Public Interest Research Group (PIRG) at Harvard will begin a door-to-door petition drive tonight in an effort to obtain the approval of half the undergraduate student body, a provision that Massachusetts PIRG requires before a chapter can be established on a college campus.

Approximately 2500 undergraduates, 73 per cent of the total needed, signed the PIRG petition last November and December in House dining halls and the Freshman Union.

Mary E. Babic '81, an organ'zer of the campaign, said yesterday the group will circulate the petition in Thayer and WeldHalls tonight. In the next two weeks the petition drive will concentrate on the Freshmen dorms and Mather, Quincy and Adams Houses.

"The strategy of going door-to-door is to explain to people exactly what PIRG is; if we contact them, they'll respond favourably," Babic said.

PIRG is a consumer protection and environmental action organization which has been organized in several states during the past six years.

After the PIRG petition receives the support of more than half the undergraduates, the campaigners plan to present the petition to Archie C. Epps III, Dean of Students, who must approve PIRG as an official student organization.

A major objection to the PIRG petitioning in the houses was the so-called "negative checkoff" provision, which adds a fee of $5 per semester to each undergraduate's term bill unless the student checks a box which exempts him from payment.

Stephen J. Morgan '70, executive director of Massachusetts PIRG, said last week that a positive checkoff provision would not be substituted for the negative one if the current petition fails to attract the necessary number of signatures, since a positive checkoff would create administrative difficulties for the PIRG staff.

Because of University regulations, the Harvard PIRG would be completely independent from the state-wide organization, with its own staff and legal experts. "Mass PIRG would recognize, however, us as a legitimate facet of their organization, and we'd hope eventually to change Harvard's rule," Babic said.