We investigate full-scale shortest-derivation parsing (SDP), wherein the parser selects an analysis built from the fewest number of training fragments. Shortest derivation parsing exhibits an unusual range of behaviors. At one extreme, in the fully unpruned case, it is neither fast nor accurate. At the other extreme, when pruned with a coarse unlexicalized PCFG, the shortest derivation criterion becomes both fast and surprisingly effective, rivaling more complex weighted-fragment approaches.
