Development methods and tools

• It's a basic principle to apply analyses that are linguistically motivated. This ensures that results can be re-used elsewhere under the same principle. Moreover, linguistic research can be built on, and the training period for linguists involved will be kept short.
  
• However, the choice of linguistic constructions to be included in the grammar is not controlled by linguistic interest, but rather by frequency in text corpora.
  
• Special focus is put on phenomena causing efficiency problems due to complex interaction. Here, pragmatic solutions have to be envisaged in certain cases.
  
• Using systematic test procedures is of central importance. Changes in certain parts of an analysis have to be checked step-by-step to make sure that the intended effect is reached, and no negative side effects occur.
  Interaction problems can only be detected and resolved if extensive test suites with carefully chosen examples are used.
• In the first phase of the ParGram project, the LFG Grammar Writer's Workbench (in Medley) was used as a development platform. Now, the Xerox Linguistic Environmenth (XLE) is applied. This system is compatible with the Medley system, however it builds on top of Unix and Tcl.
  
• The facilities that XLE provides include a sophisticated inspection tool for the output structures (packed representations of ambiguity), statistical information on parsing times etc.; basic test tools are available, refinements are being worked on.