#### Lookup Table

Table with 2^k rows can specify an arbitrary CPT, where k is number of parents of a node.

However, this is too complicated

#### Deterministic Node

“AND” gate will check whether all of them are 1,

“OR” gate will check whether all of them are 0.

However, this is too simple

#### Noisy-OR

Use k numbers to parametrize all 2^k entries.

More parents are equal to 1, the more probable that Y=1.

However, this only takes into account excitation!

#### Sigmoid CPT

Use k real numbers to parametrize 2^k elements in CPT

Also known as logistic regression in statistics,

activation function in neural networks.

Different from Noisy-OR in that this can mix both inhibition and excitation!