- Randomly - Gaussian noise with mean = 0 - Small network - Fixed sigma is fine - 0.01 - E.g. 8 layers - AlexNet - Too large - Wont converge - Too small - Gradient wont propagate back many layers ## Xavier System $$\sigma=\frac 1 {n_{in}+n_{out}}$$ or $$\sigma=\sqrt{2/n}$$ * Where $n=\text{filter size}\times n_{out}$ * And $n_{in}$ and $n_{out}$ refer to number of image channels in and out of the layer