Within the next twenty years, most of the data that we will use to understand cities will come
from digital sensors of our transactions and will be available in various forms, with temporal
tags as well as geotags in many instances. To interpret such data, we need to exploit and
extend a variety of data mining techniques through which the visualisation of correlations and
patterns in such data will be essential. The open data movement is gaining momentum (e.g.
http://data.gov.uk/) and we see FuturICT as sharply focussed on how we might integrate
such data using new forms of database design adapted to and distributed at the city-wide
scale. Moreover we also see the idea of crowd-sourcing as key to many new data sets that
will be useful to smart cities while noting that these types of interactive technologies can also
be used to elicit preferences and to engage in social experimentation with respect to what
we know and think about key urban problems. New applications which elicit quite subjective
preferences concerning happiness and associating these with places are currently being developed