Analysis of a widely publicised Science paper has found evidence that the data used in the research was faked (PDF).

The study, by researchers Michael J. LaCour and Donald P. Green, claimed that a short conversation with a gay canvasser could persuade people in favour of gay marriage, significantly more than a conversation with a straight canvasser. The paper reported that the effect was found to last in 3-week, 6-week, and 9-month follow ups and could be passed on to other people living in the same household.

While working to replicate and extend the original research, David Broockman and Joshua Kalla uncovered problems with the data used by LaCour and Green. They were initially surprised at how high the response and re-interview rates were in the original paper’s data and launched a small test run of their planned extension study.

After receiving a poor response rate from participants, Broockman and Kalla contacted the survey firm involved in the initial study. “The survey firm claimed they had no familiarity with the project and that they had never had an employee with the name of the staffer we were asking for,” they write in their report.

After digging into the data and finding more irregularities, Broockman and Kalla contacted Green, who cooperated with them in further analyses. The team found a number of serious problems, including the fact that the data was too perfect, with abnormally reliable measurements of people's opinions and no outliers. These problems suggest that the data was fabricated.

After LaCour was confronted and failed to provide counter-evidence, Green publicly retracted the paper yesterday, both on his own website and in a letter to Science. "I am deeply embarrassed by this turn of events and apologize to the editors, reviewers and readers of Science," he said in his letter.

LaCour tweeted earlier today that he is "gathering evidence and information" to provide a "single comprehensive response."

The alleged fraud has consequences not only for the scientific community and media, but also for activists using research as the basis for their campaigns. The Irish Yes Equality campaign used the research as a basis for its strategy in Ireland’s recent same-sex marriage referendum.