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2X2 Contingency Table | Event Observed | ||
---|---|---|---|
Yes | No | ||
Event Forecast | Yes | A | B |
No | C | D |
The "A" table entry is the number of event forecasts that correspond to event observations, or the number of hits; entry "B" is the number of event forecasts that do not correspond to observed events, or the number of false alarms; entry "C" is the number of no-event forecasts corresponding to observed events, or the number of misses; and entry "D" is the number of no-event forecasts corresponding to no events observed, or the number of correct rejections. This 2x2 table will be referenced in the definitions of a number of performance measures formulated for the 2x2 verification problem. These measures include percent correct (PC), probability of detection (POD), false alarm ratio (FAR), success ratio (SR), threat score (TS) or critical success index (CSI), true skill statistic (TSS), Gilbert skill score (GS), Heidke skill score (HSS), and a categorical measure of bias.
Updated: October 1, 2007
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