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<?xml version="1.0" standalone="yes"?> <Paper uid="P00-1068"> <Title>Diagnostic Processing of Japanese for Computer-Assisted Second Language Learning</Title> <Section position="3" start_page="0" end_page="0" type="metho"> <SectionTitle> 2 LTAG of Japanese </SectionTitle> <Paragraph position="0"/> <Section position="1" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.1 The Characteristic of Japanese </SectionTitle> <Paragraph position="0"> Japanese phrases are classi ed in the rst place into two categories: Yougen phrase(YP) and Taigen phrase(TP). A YP or TP has a Yougen or a Taigen, respectively, as it's head word. Yougen along with Taigen as categories belong to the category of semantically self-contained (called autonomous) words. The words, e.g. verbs, adjectives, belonging to Yougen have inflections, whereas the words. e.g. nouns, pronouns, demonstratives, belonging to Taigen have no inflection. A YP or TP consists of a head word and its sibling phrases on it's left semantically modifying the head word. And such a phrase in its turn can semantically modify an autonomous word by way of attaching a connective to it's right, forming a phrase, or inflecting the head word of the modi er.</Paragraph> <Paragraph position="1"> In general, a sentence is constructed by attaching to a phrase a few (or void of) functional words expressing the attitude of the locutor to the proposional part of the phrase ( modality ) and intention of the locution affecting the listener ( illocutionary-act marking ).</Paragraph> </Section> <Section position="2" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.2 Elementary Tree </SectionTitle> <Paragraph position="0"> Each node is expressed by a predicate formalism, in general, as following, For example, \ &quot; is a self-contained (autonomous) word and its lexical item, comprising an initial tree, is expressed by, Note that tense, aspect, polite expressions, \Ren-you (te)&quot; are dealt with as inflections just as in the classes teaching Japanese as Second Language. The lexical items are classied into several categories such as auto, link, prio, post, compo, according to the embedded tree structures.</Paragraph> </Section> <Section position="3" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.3 Tree Operation </SectionTitle> <Paragraph position="0"> In LTAG, 2 tree operations are de ned(See Fig. 2). A node of a tree is said to be substituted by another tree if the root node of the latter is successfully uni ed with the node.</Paragraph> <Paragraph position="1"> A tree is said to be adjoined with another tree if it is successfully inserted into the latter by unifying the root node and the foot node(marked ) of the former, respectively, with the separated nodes of the latter, all with a same syntactic category.</Paragraph> <Paragraph position="2"> In Japanese, a Yougen requires as adjoined modi ers Taigen phrases with connectives(e.g. Fig. 2 (1)) corresponding to the mandatory \ cases &quot; ( e.g. Fig.2 (2) ), and it also require have those corresponding to the optional \cases&quot;.</Paragraph> <Paragraph position="3"> The default order of the case phrases may be changed for the purpose of stressing or avoiding unintended modi cation. The change can be dealt with by way of permutation in uni cation.</Paragraph> <Paragraph position="4"> Another type of phrase to modify the Yougen is YP plus one of the connectives denoting cause, reason-why, condition etc.(e.g. Fig.3 (4)).</Paragraph> <Paragraph position="5"> A Yougen may be modi ed by a YP (Yougen Phrase) with its head Yougen inflection in Ren-you form without any connective(e.g. Fig.3 (3)).</Paragraph> <Paragraph position="6"> A Taigen is mostly modi ed by a YP (Yougen Phrase) with its head Yougen inflected in Rentai form with no connective(e.g. Fig.3 (2)).</Paragraph> <Paragraph position="7"> For ease and uniformity of processing, especially in the diagnostic parser, null connectives -Ren-you and -Rentai are introduced when a YP modi es Yougen and Taigen, respectively, by way of inflection(e.g. Fig.3 (3), (2) ).</Paragraph> <Paragraph position="8"> The other type of phrase to modify the Taigen is TP plus connective \ (no)&quot; denoting proprietary, kinship or whole-part relationship(e.g. Fig.3 (1)).</Paragraph> </Section> <Section position="4" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.4 Dealing with Situation - Depen- dent Expression </SectionTitle> <Paragraph position="0"> By incorporating into the feature structure an additional item expressing situational constraints, the parser has the capability of diagnosing usage of situation-dependent Japanese expressions such as giving and receiving bene ts as well as demonstratives. As for demonstratives, e.g. \ (kono-hon) &quot;, \</Paragraph> <Paragraph position="2"> cates a book located either in the territory of the locuter, the listener, or outside the both, respectively.</Paragraph> <Paragraph position="3"> In the case of expression for giving and receiving bene ts, for example as shown in Ta- null ble 1, the empathy relational constraints are embedded in each of the lexical items for the underlined word along with the case information for \ (ga)&quot;, \ (ni)&quot; Though the indicated three expressions have the same propositional function of expressing giving-bene t whose giver is x and givee is y, \camera&quot; is placed on the side of x, y, y with \angles&quot; towards y, x, x respectively. It is seen that the camera angle determines the requirement to the empathy relations(S.Kuno, 1989).</Paragraph> <Paragraph position="4"> Suppose the situation E(XjZ) <E(YjZ)is given, where X, Y, Z stand for \the nurse&quot;, \the locutor's son&quot;, \the locutor&quot;, respectively, for instance, the parser can diagnose the following.</Paragraph> <Paragraph position="6"/> </Section> <Section position="5" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.5 Composite Verbs </SectionTitle> <Paragraph position="0"> The above-mentioned expressions for giving and receiving, e.g. \ &quot; yondemorau , is an example of \composite verbs&quot; in Japanese.</Paragraph> <Paragraph position="1"> Many composite verbs can be produced with a considerable number of auxiliary verbs preceded by di erent main verbs.</Paragraph> <Paragraph position="2"> Because of the modi cation of the sense and the case control due to the auxiliary component, as illustrated in the case information column in Table1, we are forced to generate the composite tree (See Fig.4), carrying out modi cation of the meaning and the case control, before adjoining of modi ers to the com-</Paragraph> </Section> <Section position="6" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.6 Modality Words and Illocution- ary - Act Markers </SectionTitle> <Paragraph position="0"> In Japanese, \modality words&quot;are functional words expressing the attitude of the locutor towards the propositional part of the utterance, \illocutionary-act markers&quot; demands answer from the listener or expresses other intention of the locution a ecting the listener.</Paragraph> <Paragraph position="1"> Some combinations of certain adverbs and a \modality word&quot; co-occur in the position interposing that part of the proposition in which the locutor has concern. The example shown in Fig.5, \ &quot;(darou) is a modality word expressing locutor's supposition, and \ &quot;(osoraku) expresses the extent of his con dence on the supposition. The lexical item for the latter includes the demand for the modality semantics of the locutor's supposition. null English : It will probably rain tomorrow, I'm sure.</Paragraph> </Section> <Section position="7" start_page="0" end_page="0" type="sub_section"> <SectionTitle> Act Marker 2.7 Connective \wa&quot; </SectionTitle> <Paragraph position="0"> In Japanese, TP plus connective \ &quot;(wa) is frequently used. It is said that there are two kinds of usage of connective \ &quot; ; the one introduces the theme of the sentence, the other discriminatorily presents one of the cases of the head Yougen as shown, respectively, in the following cases.</Paragraph> <Paragraph position="1"> usage 1 In distinguishing between usage1. and usage2., we focus on the head Yougen of YP. If it has any un lled-case, and the semantic constraint of the Taigen before connective \ &quot; corresponds to that of one of the un lledcases, then our processor regards \ &quot;as discriminatory.</Paragraph> <Paragraph position="2"> Otherwise, \ &quot; is considered as introducing the theme of the sentence.</Paragraph> </Section> <Section position="8" start_page="0" end_page="0" type="sub_section"> <SectionTitle> 2.8 Use of a Stack in Parsing </SectionTitle> <Paragraph position="0"> For implementing a parser for Japanese, a stack memory can be conveniently employed.</Paragraph> <Paragraph position="1"> ] In processing the sentence from left to right, the candidate modi er phrases are kept in a stack memory until a possible Yougen or Taigen word appears and inspected if they can modify the word. The tree-structured features of the candidate modi er phrases popped up one by one from the stack are tried to be uni ed with those of the word, and the features of the phrases as far as the tree adjoining uni cation succeeds are integrated with the features of the modi ed word, to make a Saturated Initial Tree(SIT). The rest of the phrases of the stack are left there to be tested on the next Yougen or Taigen word which will appear later on. Any ordering of modi ers is syntactically permitted except when an undesired modi cation takes place.</Paragraph> <Paragraph position="2"> \ If a connective is found by reading one word ahead, the thus-far made SIT substitutes the left external node of the tree of the connective to make a Saturated Auxiliary Tree(SAT) provided uni cation succeeds(e.g.</Paragraph> <Paragraph position="3"> Fig.7). If the read ahead is a modality word, its yp node is substituted by the yp root of the SIT, and after interposing modality modi ers having been processed, the resulting phrase is considered SIT anew and the procedure goes to \ . If the read ahead is an illocutionary-act marker or the ending sentence symbol, and the inflection of SIT is appropriate, parsing terminates. Otherwise either of the -Ren-you or -Rentai connectives is attached depending on the inflection of the head of the SIT to make a SAT ( See Fig. 3 and Fig. 7).</Paragraph> <Paragraph position="4"> In either cases as well as the case with a non-null connective, the SAT is pushed into the stack and the procedure recurs to ].</Paragraph> </Section> </Section> <Section position="4" start_page="0" end_page="0" type="metho"> <SectionTitle> 3 Generation </SectionTitle> <Paragraph position="0"> We describe here our algorithm for generating a sentence when the semantic relation- null and Trees ship, for example as in Fig8, is given. The generation process progresses as illustrated in Fig9.</Paragraph> <Paragraph position="1"> The main stream of our generation algorithm follows.</Paragraph> <Paragraph position="2"> At rst, from the lexical database, an autonomous word is fetched, whose semantic relationship term is uni able with the root of the given semantic relationship. Letting the root and terminal node of the word be the rst and the second arguments, respectively. generate2 is called If the rst argument can be uni ed with the second argument, generation is terminated. Otherwise, the process, carrying over the second argument, searches for a prio or link word whose root node can be uni ed with the rst argument.</Paragraph> <Paragraph position="3"> If a prio word is found, letting its right ( foot ) node be the rst argument and retaining the second argument, generate2 is called.</Paragraph> <Paragraph position="4"> If a link word is found, an autonomous word is searched for whose root node can be uni ed with the left ( substitution )nodeofthelink word. Letting the word's root and the terminal node be the rst argument and the second argument, respectively, generate2 is called. Letting the right ( foot ) node of the link word be the rst argument and retaining the second argument, generate2 is called.</Paragraph> <Paragraph position="5"> In the following, searching of the autonomous word and handing their 2 nodes o to generate2 are dealt with by generate1 predicates.</Paragraph> <Paragraph position="7"> In the case of generation including modality words, illocutionary-act markers or composite verbs, the algorithm needs a little more complicated procedures.</Paragraph> </Section> <Section position="5" start_page="0" end_page="0" type="metho"> <SectionTitle> 4 Case and Semantic Pro- </SectionTitle> <Paragraph position="0"> cessing in Parsing and Generation In parsing and generation, case and semantic processing occurs by uni cation without any procedural programming.</Paragraph> <Paragraph position="1"> The initial tree structure of the lexical item of an autonomous word consists of a root node and a terminal node.</Paragraph> <Paragraph position="2"> Especially in the YP initial tree, the root node has a lled used-case slot and a variable unused-case slot as well as a variable semantic slot whose head part is lled. The terminal node has the null used-case slot and the lled unused-case slot as well as the semantic slot consisting only of the head predicate.</Paragraph> <Paragraph position="3"> In parsing, following the process as illustrated in Fig. 9 bottom up, when the foot YP node of a YP SAT ( e.g.</Paragraph> <Paragraph position="4"> ) is uni ed with the terminal node of a Yougen autonomous word ( e.g. ) , the case data, if any, ( e.g. [Y,[ (Y)], ]) corresponding to the SAT is moved from the unused-case slot to the used-case slot in the SAT root node. The semantic data from the SAT is integrated with that of the word and transferred to the SAT root. The foot YP node of another YP SAT if any, ( e.g.</Paragraph> <Paragraph position="5"> ) is uni ed with the said root node the corresponding case data, if any, ( e.g. [Z,[ (Z)], ]) is further moved from the unused-case slot to the used-case slot.</Paragraph> <Paragraph position="6"> The semantic data from the new SAT is joined with that in the previous SAT root in the root of the new SAT.</Paragraph> <Paragraph position="7"> Likewise proceeding, nally, by unifying the concatenated SAT with the root of the original autonomous word ( e.g. ), there remains in the unused case slot those case datas with no corresponding SAT which may be explained by omitted SATs or the slash case whose entity will be found in the Taigen word to be modi ed by the thus-constructed modifying YP.</Paragraph> <Paragraph position="8"> The whole semantic data from the SATs is integrated in the root node of the original autonomous word.</Paragraph> <Paragraph position="9"> The process of adjoining TP SATs ( e.g.</Paragraph> <Paragraph position="10"> ) to modify a Taigen autonomous word ( e.g. ) is similar to that for YP SATs to a Yougen word, except that no case data processing occurs.</Paragraph> <Paragraph position="11"> In generation, following the process as illustrated in Fig. 9 top-down, when the whole given semantic relationship is uni ed into the semantic slot of a Yougen autonomous word ( e.g. ), and if e.g. a link word ( e.g. ) is found with its root uni able with the root of the Yougen initial tree, the semantic expression is divided into two parts thanks to the case data ( e.g. [Z,[ (Z)], ] ), the one part ( e.g. [ ( ,Z, , )]) is transferred to the right node, and the other part ( e.g. [ (X,Z,Y),[ (Y),[ (U,Y), ( ,U)]]] ) transferred to the left ( foot ) node. From the case data of the used-case slot of the original yougen ( e.g. ), the case data corresponding to the link word ( e.g. ) is moved from the used-case slot to the unused-case slot in the left ( foot ) node.</Paragraph> <Paragraph position="12"> That part of semantics transferred to the right node is processed to nd the corresponding surface expression ( e.g. ) by constructing an SIT. The other part of semantics sent to the left ( foot ) node along with the remaining used-case slot ( e.g. [[Y,[ (Y)], ]] ) are made use of for nding a link word ( e.g. ) whose root node is uni able with the said left ( foot ) node.</Paragraph> <Paragraph position="13"> The semantics sent to the new link root node is divided into two parts; the one part ( e.g. [ (Y),[ (U,Y), ( ,U)]]) sent to the right node to form SIT and construct the corresponding surface expression ( e.g. ), the other part ( e.g. [ (X,Z,Y)]) sent to the left ( foot ) node.</Paragraph> <Paragraph position="14"> Likewise proceeding, when all the used-case data is transferred into the unused-case slot in the foot node, it may be uni ed with the terminal node of the original yougen ( e.g. ) , terminating the generation.</Paragraph> </Section> <Section position="6" start_page="0" end_page="0" type="metho"> <SectionTitle> 5 Mechanism of Semantic </SectionTitle> <Paragraph position="0"/> <Section position="1" start_page="0" end_page="0" type="sub_section"> <SectionTitle> Diagnostic Processing 5.1 Postulation </SectionTitle> <Paragraph position="0"> In our CALL system, the students are asked to ll in the blanks for composition in the given situation and context, using words from a given list. Therefore no morphological analysis is needed. In diagnosing the students' sentence, we assume that the following data is available for constraining processing.</Paragraph> <Paragraph position="1"> Semantic elements and their relationships, which should be expressed by the sentence with which the students are asked to ll the blanks.</Paragraph> <Paragraph position="2"> The list of words, to be used in the composition, corresponding to the semantic elements.</Paragraph> <Paragraph position="3"> Fig.10 is an example of relationships of semantic elements represented by a tree structure. Modifying elements are placed as the children of the parent, the modi ed elements. The list of the words to be used for expressing an element is linked to the element.</Paragraph> </Section> <Section position="2" start_page="0" end_page="0" type="sub_section"> <SectionTitle> tic elements 5.2 Principle of Semantic Diagnosis </SectionTitle> <Paragraph position="0"> After an SIT has been constructed, the diagnostic parser consults the lexicon with the succeeding word. If it is a connective, the parser tries substitution operation with SIT and, if successful, appends it to the SIT to form the temporary SAT. In case the parser fails to append the connective to the SIT, only the surface expression of the connective along with the SIT is recorded in the provisional SAT. Suppose the succeeding word was not a connective. If it was a Taigen or Yougen and the SIT is yp and its inflections is Rentai or Ren-you, respectively, then -Rentai or -Ren-you is appended to the SIT to form an SAT, even though the inflection might be incorrect. If the inflection of the SIT is inconsistent with the succeeding word or the SIT is tp, as no reasonable interpretation is possible, \Pending Connective&quot; is appended to the SIT to make an SAT. In all of the above-mentioned cases, the obtained SAT is pushed into the stack. When the parser encounters a Yougen word[]] or a Taigen word, it pops up one SAT after another from the stack and examines, locally generating surface expressions, if it conforms with one of the semantic children to the parent corresponding to the target Yougen/Taigen word. If it does, the parser adjoins the SAT to the word, after, if necessary, having corrected wrong/missing connective or wrong inflection of the SAT, thus making an SIT, including error correction messages if any. If the popped SAT does not conform with any of the semantic children, it is pushed into a temporary stack, recording the SAT as a false modi er if SAT can be falsely adjoined to the Yougen/Taigen word. In case of SAT accompanying , the parser, consulting the semantic relationship tree data, generating a related phrase, either replaces with a suitable missing connective and/or corrects the wrong inflection if necessary. When an SAT is popped up which conforms with one of the semantic children, the SATs held in temporary stack at that instance, if any, should have been obstacles for the popped up SAT to modify the target word. And they are marked \?&quot;. After all the SATs in the main stack have been examined, the SATs recorded in the temporary stack are returned into the main stack. And then the SAT constructed as explained in the above is pushed into the main stack. If, later on, the SATs marked \?&quot; are found to modify a target word, conforming to the semantic relationship, they are commented as causing modi cation crossover. Finally, if the semantic relationship requires modality expression(s) and/or illocutionary-act marker(s), the thusfar-made Yougen SIT is (recursively if necessary) substituted into the yp node of the expression(s) and, at the same time, corresponding modi ers of the expression(s) are looked for in the main stack to be popped making an SIT.</Paragraph> <Paragraph position="1"> If at []], the found Yougen word is a part of a composite verb the semantic relationship requires, the rest is looked for, supplemented if lacking, the case information is modi ed if necessary, and the same procedures follow as described after []].</Paragraph> </Section> </Section> <Section position="7" start_page="0" end_page="0" type="metho"> <SectionTitle> 6 Example of Diagnosis </SectionTitle> <Paragraph position="0"> For example, supposing the student had input the sentence shown in Fig.11, the parser could detect the errors by using the semantic relationship aforementioned in Fig.10 and the relation of the degrees of empathy in the given situation.</Paragraph> <Paragraph position="1"> The detected errors are listed in the follow- null false modi cation : Inappropriate placing \ &quot;(watashi no), causing the phrase to modify \ &quot;(hobo-san).</Paragraph> <Paragraph position="2"> missing connective : Missing connective \ &quot;(ga) which \ &quot;(hobo-san) must have for the phrase to be adjoined to \ &quot;(yo-nde kureru).</Paragraph> <Paragraph position="3"> obstacle for modi cation : \ &quot;(hobo-san) is in the place of obstacle for \ &quot;(watashi no)tomodify \ &quot;(musuko).</Paragraph> <Paragraph position="4"> wrong inflection : \ &quot;(yo-mi) has to be replaced by \ &quot;(yo-nde) for the verb to form a composite verb together with auxiliary verb \ &quot;(kureru) expressing giving bene t.</Paragraph> <Paragraph position="5"> wrong connective : Wrong connective \ &quot;(de) has to be replaced by \ &quot;(wo) which \ &quot;(hon) must have for the phrase to be adjoined to \ &quot;(yo-nde kureru).</Paragraph> <Paragraph position="6"> modi cation crossover : The sentence has a modi cation crossover between \ &quot;(watashi no musuko) and \ &quot;(hobo-san ga yo-nde kureru).</Paragraph> <Paragraph position="7"> inappropriate situational expression : Use of \ &quot;(ageru) in the given situation designates empathy relation which contradict with the given empathy relation. It requires less number of corrections for \ &quot;tobereplaced by \ &quot;(kureru) for conforming with the relation and retaining \ &quot;(musuko ni) than to be replaced by \ &quot;(morau).</Paragraph> </Section> class="xml-element"></Paper>