- computations
-
computations proportional to number of pairs (x,y).
-
could be intolerable for trigrams with vocabulary sizes
of 10's of thousands.
- other issues
-
where do we get the constraints from? do we use all of them?
-
use cross-validation to get best set of constraints
-
estimation process not simple for non-binary features
-
back-off framework not easy to introduce because of inconsistent
constraints -- problem for GIS