An interesting diagram by John Battelle found in the June issue of Wired UK (and pointed to me by Rémy)

Called "How the check-in extends the great database of human intentions", this categorization describe how user intents are made explicit by various platforms. It shows of social media make them explicit.

Besides, the "check-in" item corresponds to what I described in my PhD dissertation with "self-declaration of location".

Why do I blog this? this is connected to research issues I tackled in my research. The difficult thing would be to add a fourth line to describe the meaning of each of these signals: what inference can be drawn from my whereabouts or my interest. This is course addressed in human-computer interaction and there combination of each column can also be important.