As alluded to earlier, the model represents propositions in the passive and active voices in an identical manner. However, the model is incapable of processing sentences in the passive voice. Although passive voice sentences are not included in the grammar, the networks inability to process them is concerning due to the heavy reliance on role sequences. Despite some of these reservations, the network also has some very good properties. Obviously, the network can generalize as this was the major aim.
Generalization occurs in two ways.
Primarily, the network is capable of processing words in novel syntactic position. It is also capable of generalizing to novel levels of embedding. During training, the sentences have a maximum relative clause embedding of one, while during testing the network succeeds in processing sentences with a depth of three relative clauses. Discussion and Conclusions Hadley has certainly given us a model which attains his criterion of semantic systematicity. The network has shown its generalization power with the target grammar, although it is doubtful that the network could be extended to more complex grammars, particularly those including using a combination of passive and active voice phrases.