they are rigid and tax memory. Imagine that you’d abstract a pattern for every mor-
phological variation. Take for example the following two sentences and their respec-
tive patterns (I go to NY this summer [
I go <place> <time>] vs. I went to London last
week [
I went <place> <time> ]). It clearly doesn’t make sense here to abstract two
patterns, since the two sentences are so much alike. It would be much more reasona-
ble to have one general pattern for the global structure (person go <place><time>)
and a set parameters, i.e. rules for local adjustments, like agreement, tense, etc.
Just like patterns, rules have certain shortcomings. While they may account for the
expressive power and all the regularities of a given language, they may prevent us
from getting the job done in time, in particular if there are too many of them. This
being so, we suggest to use a mixed approach, resorting to each strategy when they
are at their best, patterns for global structures, the syntactic layout, i.e. sentence
frame, and rules for local adjustments. This combination gives us the best of both
worlds, minimizing the use of computational resources (attention, memory), while
maximizing the power (speed) and flexibility of output (possibly needed accommoda-
tions).
When people learn a new language, they build some kind of database composed of
words, patterns and phrases. This memory can consist of translation pairs, or, pairs of
conceptual patterns and corresponding linguistic forms (sentences). One can also
think of conceptual patterns as a pivot, mediating between translations of languages.
One problem with databases is access. As the number of patterns grows, grows the
problem of accessing them. This is where indexing plays a role. Patterns can be in-
dexed from various points of view: semantically (thematically, i.e. by domain), via
the words they contain, syntactically, etc. While we index our patterns pragmatically,
i.e. in terms of communicative goals (function the pattern is to fulfill), we allow
access also via other means.
To see how our model relates to the generation models presented here above,
we’ve tried as far as possible to recast it in those terms. The resource can be used
both as a translation aid, as an exercise generator (our concern in this paper), or as a
tool to extend the current database (this is work for the future).
In the first case it would function in the following way: given some user input
(sentence), the system tries to find the corresponding translation, which is trivial if the
translation is stored in the DB.
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In the second case, the assumption is that the user
knows the goal s/he’d like to achieve. Hence, the dialogue goes as follows. Given
some goal (step-1), the system presents a list of patterns, from which the user must
choose (step-2), pattern whose variables he will instantiate with lexical items (step-3)
and morphological values (step-4).
It should be noted, that in this case conceptual input is distributed over three layers: at
a global level (macrolevel) the speaker chooses the pattern via a goal, by providing
1
If the goal is the extension of the database by finding similar sentences in a corpus, i.e. sentences built on
the same pattern, the problem is harder. The program must infer or abstract the input’s underlying pattern,
and find a corresponding sentence in the target language. This sentence can be either the translation of the
input or a somehow similar sentence extracted automatically from the corpus. This is clearly work for the
future. The main part of this paper deals with the exercise generator.
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