Loss values on training and validation sets allows to see, how our model improves over the time and decide when to stop training:
from matplotlib import pyplot as plt history.history.keys() ['acc', 'loss', 'val_acc', 'val_loss'] plt.plot(history.history['loss']) plt.plot(history.history['val_loss']) plt.title('model loss') plt.ylabel('loss') plt.xlabel('epoch') plt.legend(['train', 'test'], loc='upper left') plt.show()