Less than a year after Tufts University punished a student publication for mocking the school’s affirmative-action policies, a public policy expert addressed the difficulty of defining acceptable free speech rights on college campuses at Tufts yesterday.

University of California at Berkeley Dean of Law Christopher Edley said private institutions ultimately have the right to decide what speech is appropriate because the First Amendment and academic freedom are different entities. There is a constant struggle to balance the interests of individual expression and community values, he said, adding it is constitutional for a community to define its own ethical responsibilities.

“There’s supposed to be a tension,” he said. “There’s a [struggle] how to create a community over decades where both [sides] are respected and engaged.”

Tufts President Larry Bacow said he called upon Edley to “sharpen the discretion” and “add clarity” in interpreting the university’s recent rulings on free speech issues.

Last May, the university-created Committee on Student Life found The Primary Source, a conservative campus publication, guilty of harassment and “creating a hostile environment” after publishing several anonymous stories that took controversial approaches.

An unsigned poem published last December entitled “O Come All Ye Black folk” — a spoof of “O Come All Ye Faithful” — mocked the school’s affirmative-action policies.

The May ruling condemning the publication required The Primary Source to include bylines for all written material, but that decision was reversed on appeal in August.

Edley said the advantage of a First Amendment policy at a university is that it “dis-invites the community from the process of judging the value of the content of speech.”

Though Edley said there are no guidelines to the limits of free speech that a university “can carve in concrete,” Tufts students and faculty said the school still has a lot to consider concerning free speech.

“[Edley’s] biggest statement was perhaps the most unsatisfying to hear,” said Tufts junior Estelle Davis, adding she wished he had taken a clearer side on the issue.

Tufts will continue to work to balance the freedoms of individuals and ethical responsibilities of the community, said professor Ellen Pinderhughes.

“Tufts has an important set of questions to discuss,” Pinderhughes said. “We are still finding our sense of community in terms of supporting all voices or academic freedom.”