STD Example (Pearl)
STD Example (Pearl)
- Suppose we are studying a Sexually Transmitted Disease.
- Two heterosexual males and two heterosexual females have sex with one another.
- Dependence and Independence relations are correctly described by an undirected graph via connection:
F1
F2
M2
M1
But this set of dependence
relations cannot be described
via an acyclic directed graph
with d-separation.