
216 Big Data: Techniques and Technologies in Geoinformatics
group formed around node 635 (blue cluster at the upper middle) and some other
further disjoint small clusters at the top and bottom of that gure.
Similarly to users, words are also linked, as they appear in the same messages,
to form word networks that dene the discussion themes. In Figure 11.7, we show a
snapshot of such a word network. The size of the node corresponds to the frequency
of this word, and we can see how obama is a keyword that is emerging from the dis-
cussion, followed by romnei, bain, barack, patriot, etc. Connections among words
are established every time two words ...