Statistics

The statistics option is used during training to statistically compare network predictions with training targets. For each output node and for both training and test sets, standard deviation, error bias, maximum error and the correlation coefficient is computed and displayed. The standard deviation between the predictions and targets assumes a Gaussian distribution exists in the prediction error. The bias value measures any shift between predictions and targets. This indicates whether the prediction is systematically high or low. If the error in the predictions is a true Gaussian distribution, than the bias value should approach zero. The correlation coefficient is a statistical measure of how well the predictions agree with the targets. A value of 1 indicates perfect correlation. Values close to 0 (or below for this analysis) indicate that little or no correlation exists between network predictions and targets. As with all statistical computations, validity of the calculations increases with sample size.