The second bar of each stacked cluster in Figure 1 shows
the overall number of tweets shared by each user category
for the different types of incidents. We can notice that even
though the number of the emergency management organizations
and other organizations is significantly smaller than
the number of individual users, most of the tweets are shared
from users of these organizations (overall 56%). The individual
users share 33.3% of the tweets, though, the number
of tweets by individual users regarding the shootings
is much higher. The reason for this might be that shootings
are more of public interest compared to car crashes
and fires. Furthermore, the results show that individual users
contribute only one or at most two tweets regarding small
scale incidents.
To understand who is first reporting about an incident, we
compared the timestamps of the first incident reports sent by
each user category. Figure 2 shows that 65% of all incident
types are first reported by organizational users and only 23%
of all incidents are first reported by individual users. But also
in this case, we can notice that 53% of the shootings are first
reported by individual users, which might also be the case
because of higher public attention.