# Prop Sum Normal

The prop sum normal propagation is activated either by selecting the Prop Sum Normal item of the Network Menu or by pressing the corresponding button in the Run Mode Tool Bar (see Figure 1). If you are using auto propagation, you can specify HUGIN to use this propagation method.

The “prop sum normal” is the most commonly used propagation method. It updates all probabilities, distribution functions, and expected utilities of the discrete chance nodes, the continuous chance nodes, and the decision nodes, according to entered evidence.

Figure 1: The prop sum normal button from the Run Mode Tool Bar.

A propagation of evidence does not update policies in a (limited-memory) influence diagram. To update policies Single Policy Updating should be used.