Figure 9

Robustness of timestamps. We test whether the inter-event timing distributions of ‘IBC Baghdad’ (left) and ‘SIGACT Baghdad’ (right) in the time window October 15, 2006 to February 15, 2007 exhibit non-trivial timing signatures for different timestamp uncertainty Δ. (a) shows the results for the full datasets and (b) for threshold equal to 3 casualties per event. The top panels illustrate how for 100 different redistributions (see text for details) the p-values for the test for exponential distribution of the inter-event times changes as a function of ${\mathrm{\Delta }}_{\mathrm{IBC}}$ and ${\mathrm{\Delta }}_{\mathrm{SIGACT}}$. The horizontal red line corresponds to the significance level of 0.05, below which the null hypothesis of exponential distribution can be rejected. The bottom panels show the fraction F of realizations (out of 100) for which the exponential distribution can not be rejected.