Fixed Ordering
n
Restrict to networks consistent with a
fixed
total ordering
p
of the nodes*
n
A
®
B
̃
A
p
B
n
n
Each node X
i
has a set
W
i
of at most k
possible
candidate parents
**
n
n
Number of allowed structures still exponential
* Friedman& Koller 2000, ** Friedman, Nachman & Pe’er 1999