Chart Parsing

Abstract

1 The Problems • Inefficiency of backtracking parsers; • Inadequacy of trees as representations for parsing when there are local ambiguities; • Inadequacy of trees as representations for parsing when there are incomplete structures. 1.1 Parsing inefficiency A backtracking parser may perform many redundant actions: • rediscovering phrases it has already successfully found; and • re-exploring hypotheses that have already failed. (1) Have the [ N P students that we talked about ] take the exam. (2) Have the [ N P students that we talked about ] taken the exam? (3) The cherry blossoms [ P P in the garden ], are lovely. (4) The cherry blossoms [ P P in the garden ], and a rose blooms by the house. (5) Several cars raced [ P P at the the most dangerous race track in the world ] were tested for problems.