Relevance & Research Question: People’s willingness to share data with researchers is the fundamental raw material for a lot of research. So far, researchers have mainly asked respondents to share data in the form of answers to survey questions. However, there is a growing interest in using alternative sources of data. Some of these data can be used without further issues (e.g. publicly-shared social media data). For others, people's willingness to share them is a requirement. Despite the growing interest in using and combining different data sources, little is known about people’s willingness to share these other kinds of data with researchers. In this study, we aim to: 1) provide information about the willingness of people to share different types of data; 2) explore the reasons of their acceptance or refusal, and 3) try to determine which variables can affect the willingness to perform these additional tasks.

Methods & Data: In a survey implemented in 2016 in Spain, around 1,400 panelists of the Netquest online access panel were asked about their hypothetical willingness to share different types of data: passive measurement on devices they already use; wearing special devices to passively monitor activity; providing them with measurement devices and then having them self-report the results; the provision of physical specimens or bodily fluids (e.g. saliva); others. Open questions were used to follow up on the reasons of acceptance or refusal in the case of the use of a tracker.

Results: The results suggest that the acceptance level is quite low in general, but there are large differences across tasks and respondents. The main reasons justifying both acceptance and refusal are related to privacy, security and trust. Further analyses exploring the differences in levels of willingness show that we are able to identify factors that predict such willingness (attitude toward sharing, perceived benefit of research, trust in anonymity, attitude toward surveys, etc).

Added Value: This study provides new information about the willingness of online panelists to share data, extending prior research, which has largely focused on a single type of data and has not explored correlates of willingness.