Burson-Marsteller, the largest agency, last month signed the Wirthlin Group, McLean, Va., as its exclusive research partner, replacing a similar agreement between Wirthlin and Hill & Knowlton that ran from 1987 to '93.
Hill & Knowlton, meanwhile, has signed a non-exclusive agreement with Yankelovich Partners, Westport, Conn., as Ketchum Public Relations, among others, continues to maintain an in-house research department.
PR executives say the activity stems from stepped-up client demands for accountability.
When pitching PR accounts, requests for proposals often "require an evaluation system; more and more, that's the critical thing," said one senior executive at Hill & Knowlton.
Wirthlin President Jim Granger said research among PR agencies is "historically underused."
Unlike the ad business, which banded together decades ago to create standards for research, PR has largely avoided the issue when developing a communications strategy.
"The PR community as a group did not embrace the idea of measurement or research for developing a strategy of communications," Mr. Granger said.
Instead, clients or PR agencies merely measure shifts in attitudes about a product, a company or an issue to gauge whether their efforts have been successful after the fact.
Now, PR shops are trying to re-establish their role as consultants rather than mere publicists or image makers.
"We're asking clients to consider PR to be part of the strategic brand milieu," said Jim Taylor, general manager of Hill & Knowlton's New York office, and former managing partner at Yankelovich.
But for many consumer products, it's far more difficult to isolate PR activity from advertising or other communications.
"How do you measure how a consumer got that message?" asked David Drobis, president of Ketchum PR. "As media become more fragmented, it becomes even harder."
"In package goods, you're such a drop in the ocean," agreed Richard Edelman, president of Chicago-based Edelman Public Relations Worldwide. "I'm always more comfortable in the business-to-business environment in using research to support what we do."
But some believe that measuring the value of PR isn't exactly rocket science.
"We're out there changing attitudes and creating awareness; those are easy things to measure," Mr. Drobis said.
Ketchum's Effectiveness Yardstick measures everything from a client's press clippings to behavioral shifts, in part because of a new bottom-line focus among clients on PR issues.
Others, like Wirthlin and Burson-Marsteller, say they will use a new proprietary method of measuring more subtle perception shifts but declined to elaborate.