In a Time Use Survey (TUS) respondents are asked to keep a record of their activities in a time diary, usually for 2 days (one weekday, one weekend day). Besides the activities themselves, their context also plays an important role. In a TUS, the activity and its social and spatial dimension define an episode. If one of the elements changes, a new episode starts.
TUS is a reliable method to capture micro-behavioural data on how people spend their time. People time spending is however determined by constraints which makes that individuals cannot just perform any action they want. Examples of constraints are the different social roles of a persons, but also one’s temporal and spatial locality at any moment. Thörsten Hägerstrand visualized this via his Time & Space diagram (or prism) which shows a path between different spatial localities of an activity over time, and this on the individual and household level.
Time registration is however burdensome, and solutions are necessary both to support the respondent and to higher the data quality. From the above it is clear that a solution can come from the interrelation between time and space. Today a time diary asks about people’s activities within a time frame, while the place is (just) an added context. However more accurate information on the place of being is often available to respondents via their Smartphones. These smart devices have sensors included that, amongst others, grasp the locality of the device (as a proxy of the respondent).
In order to include this information, the GeoService tool was developed under an EUROSTAT-contract. Contractors were Sogeti and hbits CV (as the Spin-off of the Vrije Universiteit Brussel).