To run inside-outside recursion, the EM algorithm employs the parameters θ based on maximum likelihood estimation; the VB algorithm employs the mean parametersθ; and our CVB algorithm employs the parameters θ CVB computed from the expected counts of all other sentences.
hence, the independence assumption in (2) and Figure 1(d) seems too strong, leading to inaccurate local maximums, although it allows for efficient and deterministic updates in EM and VB.