In using Neural Network Toolbox, does a large Mean Square Error (MSE) nullify my training result even if I have Regression R value close to 1?

I have an input 16821 x 13 and an output 16821 x 1. After training I have a large MSE for testing (1.1E8) but R value about 0.9. Can I consider my result to be good?

03 March 2015 9,757 6 View