Technological advances that have expanded the press to include new forms of broadcast and electronic media will force a redefinition of First Amendment guarantees of free speech and a free press, according to a congressional study. Written by the Office of Technology Assessment, the report said: "Many of our 20th-Century assumptions about freedom of the press depend on notions of the press as a business . . . committed to a regular cycle of publication and broadcast, managed by responsible persons, and striving . . . for objectivity, balance and a fair presentation of the facts." But the study said that new questions of liability and potential for harm may also be raised. Distinctions between primary publishers, secondary publishers and republishers--which served to allocate responsibility for defamatory publications--will be more difficult to make. The study said that limitations on the liberty of the press may arise "from a failure to reconcile private ownership interests in the physical media with public interest in the message carried over those media."