Optimising cohort data in Europe

means most consumers do not realise howmuch data is actually being captured, nor how these data are being used or shared. Examples of passive data collection are a browser or mobile device recording your location. Even though you may have clicked okay when first asked if the resource could monitor you, the device passively records your position from there on out. The strengths and weaknesses of this modality of data collection are shown in Table 3. Table 3. Strengths and weaknesses of passive data collection

Strengths

Weaknesses

− Informed users can control cookies. − The various types of data and file types that are collected can be quite complex. − Every transaction from server to client results in the creation of a log file. On any site with heavy traffic, the volume of information collected and interpreted is immense, especially when transactions involve embedded files like graphics that take up space. Processing log files can take substantial time and system resources.

− A better representation of preferences and future behaviours than with expressed opinions. − Objective measure of user experience, duration and frequency of activities, preferences and habits. − Can provide incomparably more samples over a shorter period of time.

2.4. Geospatial technologies for data collection Geospatial technology collectively refers to Global Navigation Satellite Systems (GNSS), Geographical Information Systems (GIS) and Remote Sensing (RS). A GIS is the mapping of geographical coordinates with other, mostly location-based information (Viana et al., 2017; Geospatial World, 2022). Global Positioning System (GPS), GIS and accelerometry in combination can provide a detailed picture of study participants’ interaction with their environment (Megget, 2016; Arc User 2022). Positioning technologies, such as GNSS, are a satellite constellation that transmits signals from space to users with a compatible device to determine that person’s position, velocity and time. Researchers have made use of positioning systems to, for instance, investigate the link between location and engagement in physical activity. The widely used GPS is the US-American global navigation system and GALILEO the European pendent, to name just the most relevant systems for Europe and America. Common to all is that receiving the GNSS-signals through a mobile device is a passive process, i.e. the device receives geospatial coordinates that are mapped on other information like maps, which might be available offline or online. A device using GNSS only does not send out own location data. This only happens if the user allows apps to use the data (using the location-data without authorisation of users is illegal). This is worth mentioning because many people hesitate to use GNSS because they believe their position is being tracked. GIS or spatial analytics