case systems use many readers used case system nl application interested experiences conclusions drew well details particular semantic roles nl task replies email please post summary list thanks advance _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ken barker department computer science university ottawa kbarker csi uottawa ca 613 5625800 ext 6728 ottawa canada k1n 6n5