In this paper we investigate a structured
model for jointly classifying the sentiment
of text at varying levels of granularity. Inference
in the model is based on standard sequence
classification techniques using constrained
Viterbi to ensure consistent solutions.
The primary advantage of such a
model is that it allows classification decisions
from one level in the text to influence
decisions at another. Experiments show that
this method can significantly reduce classification
error relative to models trained in isolation.