Polling experts are raising concerns about a new survey thatfound nearly 20% of American college students believe it’s appropriate to use violence to silence offensive speech.

The results of the survey have been widely cited in conservative media outlets, including by the editorial board of the Wall Street Journal, and were written up by an opinion columnist for the Washington Post.

The way the survey results have been presented are “malpractice” and “junk science” and “it should never have appeared in the press”, according to Cliff Zukin, a former president of the American Association of Public Opinion Polling, which sets ethical and transparency standards for polling.

John Villasenor, a professor of electrical engineering at the University of California Los Angeles, defended his survey as an important window into what he had called a troubling atmosphere on American campuses in which “freedom of expression is deeply imperiled”. Villasenor, a cybersecurity expert, said this was the first public opinion survey he had conducted.