Table 1. Term definitions used for the study.

		Observed yield
		Low (unbalanced)	High (balanced)
Predicted yield	Low	True positive (TP): observed low-yielders correctly predicted as low-yielders.	False positive (FP): observed high-yielders incorrectly predicted as low-yielders.
	High	False negative (FN): observed low-yielders incorrectly predicted as high-yielders.	True negative (TN): observed high-yielders correctly predicted as high-yielders.

As in medical sciences, the negative term is used in cases where no intervention is needed after diagnosis.