Table 2.

Sensitivity (the proportion of lost calves correctly identified), specificity (the proportion of surviving calves correctly identified) and accuracy (the proportion of correct predictions) of the population-level (PBM) and individual-based (IBM) methods for predicting calf survival across all data sets. For the PBM, the estimated threshold value (186.5 m/h) and the bounding values of its 95% bootstrap confidence interval are shown. For 2012 data, we assumed the predicted calving status was true and therefore included all females predicted to have calved

Performance measure	Data set	PBM			IBM
		153.0 m/h	186.5 m/h	249.5 m/h
Sensitivity	2011 (n = 4[3])1	1.0	0.75	0.25	1.0
	2012 (n = 8)	0.63	0.63	0.38	0.88
	2004 (n = 4)	0.75	0.50	0.25	0.75
Specificity	2011 (n = 8)	0.63	0.75	1.0	0.75
	2012 (n = 4)	1.0	1.0	1.0	1.0
	2004 (n = 5)	0.80	0.80	1.0	0.40
Accuracy	2011 (n = 12)	0.75	0.75	0.75	0.82
	2012 (n = 12)	0.75	0.75	0.58	0.92
	2004 (n = 9)	0.78	0.67	0.67	0.56

¹The total number of calves known to be lost in 2011 is three for IBM as we excluded the female misclassified as not calving.