NLP AI with neural networks “a black box” (Brock,
2018).
Differently from statistical NLP, deep NLU ap-
proaches, e.g. CG ones (Kiselev, 2017; Raghuram
et al., 2017), show high accuracy on the WS but can
process (i.e. their knowledge database is enough to
cover) limited numbers of WS sentences. This lim-
ited coverage results from more difficulty—than in
the case of statistical NLP—to automatically create a
database because the database has to reflect a richer
information structure of text. Deep NLU requires
more human effort to (manually) create the knowl-
edge base. As for the explainability, the CG-based AI
“thoughts” are usually clear from the data structure
and/or reasoning rules used, as for instance in the case
of the Kiselev (2017) and the AI method the present
paper proposes. Implementations of this type are re-
ferred to as explainable AI (aka XAI).
To sum it up, statistical NLP (such as ML) demon-
strates large coverage but limited accuracy and lim-
ited explainability, deep NLU (such as computational
CG) demonstrates limited coverage but high accuracy
and sufficient explainability.
2 CURRENT RESEARCH STAGE
AND TARGETS
This section identifies the AI implementation the pro-
posed knowledge acquisition method has built upon,
and outlines future knowledge acquisition research
prospects. The section ends with the question to be
empirically answered by the present paper.
The author tackles the NLU coverage issue, ex-
plained in 1, by further improving an existing AI im-
plementation. That AI (Kiselev, 2017) has shown
high accuracy in answering questions from a WS
dataset, but its CG database is limited to that dataset
only and no automatic knowledge acquisition is im-
plemented. That database is manually populated with
information structures called constructions, each of
which contains knowledge about the form and mean-
ing of a word, a phrase or a sentence. To put it differ-
ently, the database has three types of constructions:
word, phrase and sentence ones. It is important to
note that the same constructions can be reused to un-
derstand text pieces with similar form and meaning.
This paper describes the current research stage
at which the author looks into automatic acquisition
of word constructions only. They are added to the
database of the above AI and used for WS understand-
ing. Automatic acquisition of phrase and sentence
constructions are future stages of the research.
The paper is to answer the following question.
Does automatically adding word constructions to the
existing database result in any increase of the accu-
rate coverage for unknown sentences? This ques-
tion is important because the word constructions are
meant to become components of phrase and sentence
constructions by satisfying syntactic, semantic and
pragmatic requirements (listed “inside” phrase and
sentence constructions). The answer to the ques-
tion contributes to the practical value of the proposed
method applied to understanding the WS, an espe-
cially hard (Winograd, 1980) task for AI.
3 TEXT UNDERSTANDING
Before explaining how the knowledge is acquired, it
is important to explain how the present AI implemen-
tation understands text.
3.1 Knowledge Networks
First, word constructions from the database are used
to find known words. A construction is, simply put, a
collection of feature => value pairs. This is a tem-
plate so instead of the feature and value any mean-
ingful information can be used. That information is to
describe form and/or meaning of text pieces of three
types (recall the construction types mentioned in 2).
For instance, a familiar word “phone” was found be-
cause the value (i.e. the word spelling) in the pair
string => phone matched “phone” in the text. The
boldface words within boxes in Fig. 1 represent con-
structions for the known words: the implementation
now knows e.g. that “he” is a personal pronoun. It
knows because the construction that matched “he” has
the pair type => personal and the construction also
says that “he” is a pronoun.
Next, the AI checks if the found known words
(or, technically, the word constructions that have
matched the spelling) fit into known phrase structures.
Each phrase construction in the database represents a
known phrase type, e.g. the verb phrase (VP) for “call
George” (Fig. 1). These two words fit into the VP be-
cause the AI has found matching features and values.
For instance, the values action in the word construc-
tion for “call” and entity in that for “George” have
matched the same values in the VP construction; for
space considerations the figure does not show every
feature and value.
As all form and meaning requirements of the VP
to its potential components were similarly met by the
two word constructions (i.e. certain features and val-
ues were found matching), the constructions became
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