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Communicating with Databases in Natural Language - Wallace M.

Wallace M. Communicating with Databases in Natural Language - Ellis Horwood Limited, 1985. - 170 p.
Download (direct link): comumunicatingwthisdatabase1985.djvu
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Such an analysis has been used by Shank [39] in the attempt to reduce the whole of natural language to a fixed set of underlying concepts.
The problems of applying componential analysis are:
(1) That the analysis only approximates to the meaning:
the fewer the concepts, the less exactly can they represent the meaning. In Quine’s view [,37] no dictionary definition can be exact so the only set of concepts which can exactly represent all meanings is the complete language!
(2) That analysis into basic concepts is inefficient:
the single word “election” is an invaluable shorthand for all the activities that make up such an event.
No conceptual cases are used in QPROC because the general concepts — such as CHANGE — will not necessarily be represented in an existing database, A database is just as likely to have a relation which interprets the actual words used in the sentence In this case it would be more complicated, and less efficient, to allow QPROC to perform a componential analysis of the words used in each query, and then to recombine the concepts so as to map them onto relations in the database.
2.4 The internal structure of verb modifiers
It has been left, so far, unclear what grammatical structure can serve as a case for a verb. The logical-object, for example, is generally a noun phrase:
“Smith gained Worthing from whom?”
“Which constituency was lost by the liberals?”
92 SEMANTICS
[Ch
Other cases are often composed of a preposition (“from”, “by” etc) followed by a noun phrase (“from whom”, “by the liberals”).
Certain verbs, however, include a “that-object” case;
Frank
logical-subject
hopes that John is sleeping that-object
or an “ing-object” case:
Fred
enjoys going to the theatre ing-object
logical-subject
Such verbs are interpreted in generative grammar as a predication (see for example [.3.3]) (Fig. 5.12).
(1)
There is no standard way of mapping these onto relations with attributes defined on simple domains. The main predicate in these predications is “hope” and “enjoy” respectively, and their second argument must be a predication One way of dealing with this is to associate the second argument with the domain of ‘events’. Each ‘event’ value identifies a tuple in an ‘event’ relation, so clearly ‘event’s have a fixed set of attributes. Such a technique is not applicable to current relational databases, because there is no such generalised interpretation of an “event”.
PREDICATE AGENT
THAT-OBJECT
[hope] [Frank]
PREDICATE AGENT
[sleep]
[John]
(2)
PREDICATE AGENT
ING-OBJECT
[enjoy] [Fred]
PREDICATE AGENT GOAL
[go] [Fred] [theatre]
Fig. 5 12 - “Predications”
5]
SEMANTICS 93
Research is taking place on the logical representation of events [31] but it may yet be some time before the fruits of such research can be utilised in transportable natural language front ends Because there is no general semantic apparatus to deal with predications, it was decided that QPROC need not deal with sentential complements (‘that-objects’, ‘ing-objects’, etc). However, any natural language front end must be able to deal with certain words taking constructions of this kind, e.g,
“Is it true that Collins serves ICL7”
“Tell me if desks are over ?50. ”
2.5 Interpreting a sentence
The interpretation of a sentence or clause is a formal QUALIFIER in the language of D&Qs (Chapter 4) A simple sentence, or clause, comprises a verb and a number of verb modifiers. The verb is interpreted as a formal relation, and the verb modifiers supply attribute values for that relation. The interpretation of each verb modifier is a pair: ‘(Grammar,Description)’, ‘Grammar’ is the grammatical case of the verb modifier, and ‘Description’ is the interpretation of a noun phrase, (see section 4, below). The simplest form of DESCRIPTION is a data value, such as ‘labour’, or ‘1974’, Thus if “to buy” is interpreted as the relation ‘deal’, the query;
“Did John buy the widget before 1974?”
has an interpretation equivalent to the formal qualifier:
‘John’ is qual(Yl, ‘widget’ is qual(Y2, ‘1974’ is qual(Y.3, deal(purchaser =Y1, part = Y2, date = Y3) )))
Although QPROC’s analysis of a sentence does not use surface cases, the syntax of compound QUALIFIERS allows the traditional grammatical categories of subject and verb-phrase to be mirrored in the formal interpretation. Returning to the example
“Every boy loves a girl”,
Descl is qual(Vl, Desc2 is qual(V2, Qual))
‘Descl’ is the formal description interpreting the subject (“Every boy”), ‘Desc2’ is the formal description interpreting the object (“A girl”), and ‘Qual’ interprets the verb phrase “[VI] loves [V2] ”,
Because the formal interpretation reflects traditional grammatical categories, it is very simple to deal with conjunctions such as “Who was 54 and stood at Worthing?”
“Who” is the grammatical subject and has interpretation ‘Desc’. “[Y] was 54”, and “[Y] stood at Worthing” are each verb phrases and have interpretations ‘Quail [Y] ’, and ‘Qual2[Y], Thus the whole sentence is interpreted as
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