Optimising cohort data in Europe

characteristics of social media communication. In the absence of bodily language information (e.g. posts on a forum), social communications become ambiguous and thus may lead to various communication mistakes (Arigo et al., 2018). Researchers should be thus aware of the potential limitations of online data before using them in their research. Another issue of social media concerns the kind of data that can be used and collected for cohort data studies. For instance, an alternative to interviews is to use materials that individuals have already posted online (e.g. forums, blog diaries). However, this presents ethical problems: is it ethically justified to use data that were not generated for a research purpose? Participants have no objections for this type of data to be used without consent as long as it is restricted to general aggregated research purposes (Segura Anaya et al., 2018). Opinions are however less clear cut with regards to anonymity and consent for a more specific research purpose: some respondents think that their data cannot be used without consent while others do no insist on it (Genviève et al., 2019). In any case, because there is still no consensus about the ethical approach for this kind of data, researchers should closely negotiate with the participants in relation to their preferences for data use. An important problem with passive data collection is that it is difficult to obtain legitimate informed consent. In cases where consent is thought out from smartphones or/and smart devices for instance, people tend to not read the consent forms and agree to terms reflexively (Cvrkel, 2018, cf. also Section 3.2). This means that the participants are not aware of the ways in which their data would be analysed, shared and used. Geospatial data collection technolgies display similar problems. That is, the very nature of geolocation devices means that participants cannot possibly grasp the full extent of the data they provide. In this context, the nature of consent has to be re-conceptualised so that participants would be able to take informed decisions at any time (Nebeker et al., 2019). 3.4. In summary: recommendations and prospects Some of the concerns and challenges arising from the above points are set out below: y y The extension and development of communication devices allow us to update the existing policy frameworks based on the Web 1.0 Internet paradigm (Izmailova et al., 2018). Namely, the Web 1.0 framework frames antitrust, privacy and user competence issues in terms of a stable divide between legal institutions on the one hand, and policy responses on the other (Gostin et al., 2018). In this context, communication technologies can potentially contribute to a harmonisation between policy and institutional responses by giving access to previously inaccessible types of personal data (e.g. lifestyle data) (Cvrkel, 2018). y y Data collection and data use are not neutral and hence, the decisions researchers make can either support or harm vulnerable communities. There is a clear danger that participants and communities can be excluded from decisional processes, which in turn, increase their powerlessness in relation to their own data (Copes et