Scientific papers include an abundance of information about methods and results. But sometimes more background details are sought by interested parties in order to precisely replicate the experiment described. However, authors seem less willing to share these additional details about their study protocols than they have been in the past, according to a survey of 389 authors who published studies in the Annals of Internal Medicine. The findings, presented on 9 September at the International Congress on Peer Review and Biomedical Publication in Chicago, found that over the five years studied the percentage saying they would be willing to do so has dropped from almost 80% to only 60%.

A lack of incentives for sharing might be partly to blame. “There's no recognition, no promotion and no profit for scientists who share more information,” says Steven Goodman, a clinical research expert at Stanford University School of Medicine in California, who was part of the team that evaluated the survey results.

The challenge of accessing extra information not detailed in research papers is further exacerbated by time, according to a study presented at the peer review congress in Chicago by Timothy Vines, a managing editor of Molecular Ecology, based in Vancouver, Canada. Vines and his colleagues tried to contact the authors of 516 papers published between 1991 and 2011 that used what is known as a discriminant function analysis (DFA) on morphological data from a range of organisms. The likelihood of a successful background data request declined by 7% a year going backwards in time, as many of the authors reported that the information was lost or on inaccessible hardware. Vines says that the results of his study should spur action: “This is exactly why journals need to enact and enforce mandatory data-archiving policies.”