A highly publicized study that purported to show how face-to-face interactions can change people's views on
The study, published in December by the journal Science, claimed that when gay canvassers in Los Angeles County knocked on a door and lobbied a household resident about same-sex marriage, the resident was more likely to form a lasting and favorable opinion of gay marriage than if they were lobbied by a heterosexual canvasser.
Coauthors Michael LaCour, a doctoral candidate in political science at
But as the report was covered by news organizations nationwide -- including the Los Angeles Times -- another group of researchers began to question its findings.
Green said that two graduate students at UC Berkeley recently approached him with a list of irregularities they found in the data.
When LaCour's advisors at UCLA reached out to him Monday, he was unable to provide the data he claimed he had collected for the study, including contact information for survey respondents, Green said.
"I write to request a retraction," noted Green in a memo to Science on Tuesday. "I am deeply embarrassed by this turn of events and apologize to the editors."
In an email sent Friday to The Times, LaCour, who has hired an attorney, said that he would provide a definitive response to the critique on or before May 29.
In the meantime, he said, on Thursday evening he sent a message to Dr. Marcia McNutt, editor in chief of the journal Science, "providing information as to why I stand by the findings" and requesting that if the journal printed Green's retraction request, that it also publish a defense from LaCour.
Earlier this week, McNutt said in a statement that the journal "takes this case extremely seriously and will strive to correct the scientific literature as quickly as possible."
"No peer review process is perfect, and in fact it is very difficult for peer reviewers to detect artful fraud," McNutt said. "Fortunately, science is a self-correcting process; researchers publish work in the scholarly literature so that it can be further scrutinized, replicated, confirmed, rebutted or corrected. This is the way science advances."
On Wednesday, the journal published an "Expression of Concern" to alert readers that "serious questions have been raised about the validity" of the study and that Green has requested a retraction. "Science is urgently working toward the appropriate resolution, while ensuring that a fair process is followed," the note said.
The study also reported that the 20-minute doorstep conversations had a measurable "spillover effect," in which some household residents who did not speak with the gay canvasser also formed a positive opinion of gay marriage.
In total, about 9,500 voters from Los Angeles County were involved in the study. The research was conducted in 2013 during the month leading up to a U.S. Supreme Court decision that effectively overturned
David Fleischer, project director of the Los Angeles LGBT Center Leadership LAB, said the group was "shocked and disheartened" by the turn of events.
"We are not in a position to fully interpret or assess the apparent irregularities in the research as we do not have access to the full body of information and, by design, have maintained an arm's-length relationship with the evaluation of the project," he said. "We support Donald Green's retraction of the Science article and are grateful that the problems with LaCour's research have been exposed."