Industrial Parsing of Software Manuals

of the parser in recognising the prescribed features. At various points, decisions had to be made about what counted as a given feature. We have taken the category of verb to include auxiliary verbs, and also present and past participles where these are constituents of a verb phrase but not otherwise. Thus \the sun is rising" contains two verbs, while \the rising sun" contains none. In the category of noun we have included: verb nouns such as \hunt-ing" in a phrase like \the hunting of the snark", proper nouns, and also phrases like \Edit/Cut" in sentence L24. We have excluded pronouns (though these have the same category as noun in our parsing scheme) and also nouns used to modify other nouns such as \source" in \source sentence". We have taken compounds to mean strings, mainly names, which are indivisible units from the grammatical point of view but are written with white space between them; examples in the IPSM test set are \Word for Windows 6.0" (T2) and \Translate Until Next Fuzzy Match" (T8). ALICE attempts to identify such phrases in preprocessing, using capitalisation as the main clue. A number of questions arise in evaluating the analysis of phrase boundaries. Our categorial formalism commits us to a subject-predicate analysis which is equivalent to a set of PSG rules of binary form only, so that for instance a conjunction of sentences has to be analysed as the application of \and" to one sentence to produce a modiier of the other sentence; but from a grammatical point of view it is an arbitrary choice which sentence is seen as modifying the other. Other examples of arbitrary choices involve attachment, where very often there is no semantic diierence between diierent ways of bracketing a sequence of noun or verb modiiers (the problem of \spurious ambiguity"). It is thus not possible to compare an actual parse with an ideal parse, because there is often more than one correct way of parsing a sentence. Furthermore, our formalism commits us to deep rather than shallow nesting of phrases inside each other, so that errors are very liable to be propagated upwards: for instance, where a verb fails to attach to one of three arguments, the three phrases in which the argument should have been nested will all be wrongly analysed. We have therefore chosen to assign scores to boundaries between words. Any two neighbouring words will belong …