I'm trying to design a neural network using nntool of matlab R2015a having input layer of 27 neurons, output layer of 2 neurons and one hidden layer of 10 neurons.I have scaled the input and output data to (0,1) for logsig activation function of hidden layer with purelin in the output layer.For tansig activation function in hidden layer i have scaled the data to (-0.5,0.5). I have trained the network with 1155 training patterns. My mse and R are very good,but the network is not giving the expected result when tested with new data. I have tried almost all the combinations possible from the user inerface(nntool) and in a great confusion. It would be very helpful if answered.