Fig. 6

Plot of event caught percentages from the Farrington event detection variants. Scores were higher when a long-term trend was included (filled circles) than when no trend was included (hollow triangles). Event caught rate fell as more years of historical data were included (x-axis), especially in variants that did not include a trend. Within each trend set, scores were higher with 4 to 12 periods for seasonality (blue to green colors), and lowest with one period, i.e. no seasonality (dark purple). The number of alarms generated is indicated by the size of the marker and decreases as more years of historical data are included