Features used in the preposition error correction system trained discriminatively. wB and wA denote the word immediately before and after the target, respectively; the other features are defined similarly. compHead denotes the head of the preposition complement. wB&compHead, w2BwB&compHead are feature conjunctions of compHead with wB and w2BwB, respectively. Adapted models also use the author's preposition as a feature.
| Feature Type . | Feature list . |
|---|---|
| Word n-gram | wB, w2B, w3B, wA, w2A, w3A, wBwA, w2BwB, wAw2A, w3Bw2BwB, w2BwBwA, wBwAw2A, wAw2Aw3A, w4Bw3Bw2BwB, w3w2BwBwA, w2BwBwAw2A, wBwAw2Aw3A, wAw2Aw3w4A |
| Preposition complement | compHead, wB&compHead, w2BwB&compHead |
| Feature Type . | Feature list . |
|---|---|
| Word n-gram | wB, w2B, w3B, wA, w2A, w3A, wBwA, w2BwB, wAw2A, w3Bw2BwB, w2BwBwA, wBwAw2A, wAw2Aw3A, w4Bw3Bw2BwB, w3w2BwBwA, w2BwBwAw2A, wBwAw2Aw3A, wAw2Aw3w4A |
| Preposition complement | compHead, wB&compHead, w2BwB&compHead |