Figure 1.
Procedure used to analyze data sharing in papers regarding human genetic variation.
We retrieved a total of 1187 papers indexed between 1st January 2008 and 31st December 2011 in the PubMed using the key words “mtDNA human populations” and “Y chromosome human populations”. We set the following limits: “humans” for species and “English” for language. The procedure used for data request by email is described in figure 2. E-mails “will provide on request” were sent to the corresponding authors to request information from papers where data availability upon request is explicitly declared; E-mails “all authors” were sent to all corresponding authors who withheld datasets.
Figure 2.
Procedure used to request data from corresponding authors of withheld datasets.
The first two e-mails were sent by the first author (nicola.milia@uniroma1.it) of this paper, while the third one was sent by the corresponding author (destrobisol@uniroma1.it). The data collection was closed five weeks after the first request. E-mails “will provide on request” were sent to the corresponding authors of papers where data availability upon request is explicitly declared; E-mails “all authors” were sent to all other corresponding authors who withheld datasets.
Figure 3.
Sharing rates in published datasets regarding human genetic variation.
Vertical bars indicate 95% confidence intervals. Separate results for mtDNA and Y chromosome polymorphisms are reported in Table 1. (A) In the “Immediate sharing” category, we reported the rate of datasets shared in the main text, its supplementary material or online databases which were explicitly indicated in the paper; E-mails “will provide on request” were sent to the corresponding authors to request information from papers where data availability upon request is explicitly declared; E-mails “all authors” were sent to all corresponding authors who withheld datasets. The results reported in frames B, C and D were obtained using the sharing rates obtained including the positive answers to E-mails “will provide on request”. We considered as negative the responses where authors asked for detailed information about the use of datasets and/or requested coauthorship before sending data. (B) Datasets were assigned to each research field according to the research aims, as stated in the paper. When assignment of a given paper to more than one field of research seemed to be possible or research aims were ambiguous or not explicit, the ISI category of the scientific Journal was used as an additional criterion. (C) The type of editorial policy was rated using the information provided in the guide to authors: weak editorial policies are those where the authors are invited to share data, whereas in strong policies, data sharing is indicated as mandatory. (D) Ranks were based on impact factor values released by ISI Reuters in June 2009.
Table 1.
Data sharing rates in studies of genetic variation of mitochondrial and Y-chromosomal variation in human populations.
Table 2.
Types of data sharing (absolute values) in the examined dataset.