Table 2.

Prediction error of mean weekly incidence predictions for Liberia using the 3 forecast scenarios. Prediction error, calculated as the ratio of the difference between predicted and observed incidence to the observed incidence, in percentage (%), is shown for forecasts initiated August 17 through September 21, 2014.

		Date of Forecast
Observation Date	Scenario	Aug. 17	Aug. 24	Aug. 31	Sep. 7	Sep. 14	Sep. 21
Aug. 24	Improved	-2.31
	No Change	1.60
	Degraded	5.85
Aug. 31	Improved	-3.36	0.50
	No Change	8.05	4.61
	Degraded	23.39	9.16
Sep. 7	Improved	0.05	4.05	4.27
	No Change	22.14	16.53	8.56
	Degraded	60.90	33.73	13.34
Sep. 14	Improved	1.80	5.05	4.43	0.40
	No Change	37.25	28.39	16.99	4.05
	Degraded	118.88	71.15	34.59	8.17
Sep. 21	Improved	9.25	11.34	9.27	2.06	0.71
	No Change	62.80	49.71	33.51	12.88	4.67
	Degraded	226.75	144.90	78.67	28.18	9.43
Sep. 28	Improved	26.74	27.09	22.83	10.59	6.83	3.75
	No Change	109.11	89.23	64.84	32.19	19.04	8.41
	Degraded	430.32	292.14	171.18	72.60	39.35	14.91