We basically used the same algorithm as Algorithm 1 for acquiring the knowledge for case alternation, but used different constraints on case alternation patterns because possible case alternation patterns are different from those of active-passive alternation.
we replaced the third and fourth lines of Algorithm 1 with "for each c to ga ∈ {NIL, ni}" and "for each c ga to ∈ {wo, ni}," respectively, based on linguistic analysis of active-causative alternation in Japanese.