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<?xml version="1.0" standalone="yes"?> <Paper uid="C82-1052"> <Title>FORMALIZATION OF ~ATION IN NEWSPAPER TEXTS Dietmar F.Roesner Math. Institut A</Title> <Section position="3" start_page="0" end_page="325" type="metho"> <SectionTitle> 2. Understanding ar~nentstion </SectionTitle> <Paragraph position="0"> In our view, argtm~ntation schemata in general work on a kind of &quot;theory&quot; of the domain of discourse, i.e. on a structure that encodes knowledge about domain-specific dependencies. We use a dependency-network in order to represent the average reader's expertise and qualitative reasonin@ ability about the jobmarket.</Paragraph> <Paragraph position="1"> Our representation is influenced by ideas from \[Sussman&Steele 1980\].</Paragraph> <Paragraph position="2"> In some sense, one may interpret an argtm~ntation schema as a function that takes propositions (<PROP>s) as arguments. In case of coherent or correct use, these propositions have to fulfill certain constraints that are defined with reference _ to the &quot;theory&quot; of the specific domain of discourse.</Paragraph> <Paragraph position="3"> Thus, wundersta~ir~&quot; ~tati(m~ in terms of these schemata can be seen as establishing the constraint relations between given propositions by an inference mechanism that operates on the dependency net of the domain. This always involves testing on discourse coherence (if it is assumed to have a correct &quot;theory&quot;) and/or checking the &quot;theory&quot; (if it is assumed to have correct texts).</Paragraph> <Paragraph position="4"> 326 D.F. ROESNER and J.H. LAUBSCH 3. Explanation schemata Explanation schemata deal with reasons - in cur domain these are mostly reasons for the jobmarket fluctuations under discussion. Although we use German surface-oriented labels (which we transcribe into ~glish), we are discussing all of the following examples as deep structures that may be underlying to diverse surface constructs.</Paragraph> <Paragraph position="5"> ~i> <PR~a-2>': (~-OF <PROP-l> <PROP-2>) This is a general explanation schema. If used correctly, then <PRUP-I> gives reason(s) for <PROP-2> : If <PROP-l> is a &quot;simple&quot; fact in our theory, then there must be an inference path in the dependency net along cause-effect links leading from <PROP-l> to <PROP-2>. If <PROP-I> is a conjunction of two (or more) &quot;simple&quot; facts, then inference paths starting from those points must interfere in such a way that they finally lead to <PRDP-2>.</Paragraph> <Paragraph position="6"> Among German surface triggers for the BECAUSE-OF-schema are: &quot;WEGEN ...&quot;, &quot;WL &quot; ...&quot;, &quot;DA ...&quot;, &quot;DURCH ...&quot;, &quot;AUFCAqD%D %~N ...&quot;, &quot;INFDLGE DES ...&quot;, but also more elaborate ones like &quot; ... DARAUF ~EN DASS ...&quot; or &quot;... DAMIT ~EN</Paragraph> </Section> <Section position="4" start_page="325" end_page="325" type="metho"> <SectionTitle> DASS &quot; <PROP>': (MOREOVER <PROP>) </SectionTitle> <Paragraph position="0"> This schema may be used if we are discussing a complex situation where consequences of several factors interfere and where the already mentioned (or derived) propositions are not sufficient to explain a given result. <PROP> must satisfy the constraint that it gives additional supportive reason for an unexplained effect, i.e. <PROP> opens a new inference-path in the dependency net such that interference with previous i~lete paths is possible in a way which finally produces the explanation that is searched for.</Paragraph> <Paragraph position="1"> <PR~*-I> <PR~*-2>': (ALTH0\[K~ <PROP-l> <PROP-2>) This sch~na deals with expectations and their non-fulfillment. Other surface manifestations are constructs like &quot;O~90HL <PROP-l> <PROP-2>&quot;, &quot;UNGEACHTET <PROPi> <PR0P-2>&quot; or &quot;ZWAR <PROP-l> D~k%X3CR <PROP-2>&quot;.</Paragraph> <Paragraph position="2"> The relation between <PROP-l> and <PROP-2> in an ALTB0t~H-schema involves a third proposition <PROP-2'>, whose constraints are: a) <PROP-2'> is in a contradictive relation (e.g. negation) to <PROP-2> b) <PROP-2'> could be expected as a (default) conm ~uence of <PROP-l> (or in other words: (BECAUSE-OF <PROP-l> <PROP-2'>) could be verified).</Paragraph> <Paragraph position="3"> In coherent texts the contradiction between expected and actual development given with an ALTH0t~R-schema will demand further explanation. ~0~@exsta~ing&quot; ~lamat/cm thus involves answering the following questions: AI: ~lat was the unfulfilled expectation <PROP-2'> contrary to <PROP-2>? I%2: Why did the expectstion~s) <PROP-2'> fail? A3: ~at caused the fact(s) of <PROP-2> to happen? Until we cannot sufficiently re=.x)Ive these explanation tasks, the ALTH0t~B-sche~a will keep active and guide the processing of further input.</Paragraph> <Paragraph position="4"> 4. A detailed example In order to clarify our _approach, let us trace the processing of the flow of argumentation in an actual newspaper article (taken from &quot;Stbttgarter Nachrichten&quot;, March 7, 1979).</Paragraph> </Section> <Section position="5" start_page="325" end_page="325" type="metho"> <SectionTitle> ARGUMENTATION STRUCTURES IN NEWSPAPER TEXTS 327 S~_= TRDTZ DES ANHALT~-NDEN ~ IST IN DER BUNDESREPUBLI K DIE AK~EITSLOS~ZAHL IM FEBRUAR LEICHT Z~KG~GANGEN. (Englo : In spite of continuing </SectionTitle> <Paragraph position="0"> winter weather the numbe~ of une~@loyed in the FRG decreased slightly in february. ) Input to the inference machine is vmitten in a surface-oriented frame notation (~-~hich could e.g. be produced by a semantic ATN-grammar). The representation of S1 is: processed by &quot;specialists&quot;~ edegg~ IH FEBRUAR is interpreted - aocording to a default text convention - as publication year's february.) The first step in processing AL~THOL~JH-I is to construct PROP-2' as a negation of PROP-2.</Paragraph> <Paragraph position="1"> In this case, the &quot;subject&quot; of PIRDP-2 is &quot;CHANGE-I NR-~ (IN ~ FIRG IN FEBRUARY ..)&quot;, whereas the &quot;predicate&quot; is the filler of the VALUE-slot, idegeo SLIGHT-DECREASE. The procedure for generating a candidate PROP-2' preserves the &quot;subject&quot;, but negates the &quot;predicate&quot;.</Paragraph> <Paragraph position="2"> What is the negation of a SLIGHT-DBCREASE? For pur~s of qualitative reasoning, we take VALUEs for CHANGEs frcm a five point scale from &quot;++&quot; (~-INCRFASE) to &quot;~&quot; (~-DECRFASE), i.e. &quot;-~ corresponds to SLIGHT-DECREASE. Interpreting negation of SLIGHT-DECREASE as simply taking the complement of {-} with respect to t/~e set of all VALUES = {++, +, 0, -, --} would yield I~-DECREASE L%ICHANGI~) SLIO}Ff-~ ~-INCREASE\], but a constraint for surface constructs allows us to exclu61e IARGE-DECI%EASE in this case.</Paragraph> <Paragraph position="3"> If a larger value had been expected (and not the opposite direction of change), then this would have been indicated by a modifier like &quot;NUR&quot; (EngI.&quot;ONLY&quot;) as in:</Paragraph> </Section> <Section position="6" start_page="325" end_page="325" type="metho"> <SectionTitle> TIIOTZ DER SAI~E IM OK&quot;rOBER STIES DIE ARBEIT~LOSEN~ IN DEM MZX~IAT NUR IIM </SectionTitle> <Paragraph position="0"> 0oi AUF 3.3 PROZENT AN (from &quot;Stuttgarter Nachrichten&quot;, Nov. 7, 1979). (\]~gl.: In spite of change of season in October the unemployment rate only increased by 0oi to 3.3 percent during this month.) Thus: the structural analysis yields</Paragraph> <Paragraph position="2"/> </Section> <Section position="7" start_page="325" end_page="325" type="metho"> <SectionTitle> QUANTITY: NR-~LOYED VALUE: (O~F {0 + ++})) </SectionTitle> <Paragraph position="0"> The next step in order to answer A1 is: Can PROP-2' be expected given PROP-l? Indeed: we find a (generic) default rule in our dependency net, that relates WINTER WEATHER with a (~IANGE of NR~~.</Paragraph> <Paragraph position="1"> 328 D.F. ROESNER and .LH. LAUBSCH I i=.=...= i I TYP: WINTER) d>fault e~tati>n path QUANTITY: NR~ I wu~: C~ {+ ~}) The next t~o sentences only give further details of the change and are no~. interesting for the present discussiondeg ~NTWICKLUNG&quot; (this development) is interpreted as referring to the already mentioned changes: the actually, happened SLI~D-DECRF~%SE (CHAh~-I) and the expected, but unfulfilled h-qCRFASE of the (global) NR-\[rN~v~LOYED (C~I~N~E-2)o This &quot;reference by abstraction&quot; is often found in r~e~,~spaper texts \[l~)senberg 1977\] o Next step: Can we infer any of these changes from BECAUSE-OF-I~s PROP-l? \[,bre specifically~ How may bKIN-INCRFASE of NR-\[rNEMPLOYED in OUTG~'~DR-JOBS e~,-plain CHANGE-I or CHANGE-2? Since $4 gave no contrary info_~aation, CHANGE-3'S TIb~-siot is filled with FEBRUARY which is the context default established by the preceeding sentences. If taken in isolation, NfLN-INCREASE for (XS'IDGOR-JOBS gives no direct ,~y to infer the Overall SLIGhT-DECREASE stated with CH~NGE-Io But: Since these two changes are given as facts and since outdoor-jobs are a subset of all jobs~ ~ co~clude~ that there must have been an interfering DECREASE in (an)other part(s) of the jobmarket, and therefore c~eate an expectation E1 for subsequent information of this kind, by the rule IF (91obal result is: DECRFASE) & (local change is- INCREASE or kAqN-DECRF~E) (expect: local DECRFI~E in other \[~rts),, With regards to CHA_NGE-2, we take a ~blo,:~-up&quot; (using a shorthand notation) of our default expectation path betweec, winter weather and global increase:</Paragraph> </Section> <Section position="8" start_page="325" end_page="325" type="metho"> <SectionTitle> ARGUMENTATION STRUCTURES 1N NEWSPAPER TEXTS 329 </SectionTitle> <Paragraph position="0"/> <Paragraph position="2"> G~>~e the dependency net is built in various levels of detail~ any &quot;non-primitive&quot; %aticn can be ~blown up~'~ idegedeg be locked at in more detaildeg ?~:~,chi~@ '/hrough possible paths relating WINTER ~ to expected INCRFASE NR- null ,. ~.~C:?LO~_ED Gh0BAL, the bl~e-up procedure selects the one with an intermediate node .&quot;,~~cerning C%HANGE-3'S QUANTITY, i.e. NR~LOYED for OU~IDOOR~deg i '~ ;:~ in D~X3~SE-OF-I a N~'~-INCREASE for OUTDOOR-JOBS ~ NR-UN\]KMP~ is given as f~:~to %~his has two consequences: ~.) The expectation path based o a ~NCREASE of this number is made invaliddeg This ,in.ers question A2 still pending from ALTHOL~-I: Diny did PROP-2' fail? 2) S.~-ce a,~ ,.~CR~SE of this number ~s expected by default~ we create a nPSw ,~?'~:~,,ah\[on task (that affects processing of subsequent input): K~nat are the ._u. u~ for. C~GE~-3 (k~J~-~CREASE of NR-UN~PLOYED (DTDOOR-JOBS in FEBRUARY)? ~; r.c\[E P.~URDkN ~;~q Dk~ 0t-~-~Y/~qD~qNLICH ~ D/IN'I~RS BEREITS IM JANUAR '~,~A~S~sq,&quot;(Ph~gl:&quot;Due to /he unusually strong winter they had been layed off $,1' eo~y in Ja,luary&quot;.) i?, ,.::J~qE-OF-2 PI,;2-2: (!~Y-OY~-I G~UP: ~I~IS* 'l'!&quot;.'~\]': * ('1&quot;IV\] JAk~TAR) ~:) ) &quot;~n O--C~e,~ to a-~-cept BEC~USE-OF-2~ we have to sh(~% that its PRDP-I leads to the e~cpectation of its P~P-2~ Searching through our d<mmin knowledge for relations betwaen ~%,~ ~nd LAY-O~'F of a GF~JP of persons gives:</Paragraph> <Paragraph position="4"> I** order to use t/,is genetic rule ~ should be able to resolve the missing refe~er~ce from IAY-O~F-I's GROJP-slot (c.T~LIS*) with ~R-WORKERS. This choice is indeed supported bY ti~e fect that CFOTDOOR-JOBS are under discussion in CHANGE-3o Since CHANGE-3 (t/-~e NO~,~-ISq~R~I~E of k~-UNEMPLOYED of OUTDOOR-JOBS) is not yet e~.plained, we u~e an appropriate blo~-;,-up of dependencies again: For JANOARY %~e have an instantiateL ~L~AUSE-OF-relaticn beh-~een ~rlT~TER and a stated IAY-OFF of ~A-WOR~So ~n inference rule for iAY-O~-~J is~ IF '-~.ere are layoffs (and no in~o~.~ation ab~J~= interfering nsw hirings) the number of ~rkers in the \[espzctive re~.:1on, branch etCo 6ecreaseSo As a consequence of the O~;~t7 I::~Y-~::~ ~ thus conclude, that the ~T}~E ARE STILL OOIDC~R-~?0~&quot;-~?~NSTPS'RA\]:~ \[~ay no ionc3er hold i~ ~PCfo This invalidates the inference path above~ th~s su~ficienkiy ~=xplainin 9 C~iANGE-3o This in turn all(x.~s us to finish proc~.ssing of Bh~U~SE-O.?-!~ Recall: Question A3 from ALT~IOU~I- null If a proposition is modified wit\]\] &quot;D~BLiCb~:'~iS~ := (engi: by default) we process it as stating a fact. The abstract description for the TIME period matches FEBirUARY, ~hich is also the filler of the ~i~\[E-slot of the still unexplained ~-io ~he function of the PROP of a MOREOVER is to give additicnal information that helps answering open questions.</Paragraph> <Paragraph position="5"> In fact, CHAk~E-4'S information answers ALTHOUGH-I's question A3~ DECREASE of NR-UNEMPLOYED for ~X~I~-fDLIAR-JOBS in FEBRUARY matches expectation E1 (D~CREASE in l~3N~R-parts of the job-market). E1 on the other hand has been set up when processing BECAUSE-OF-I in locking for reasons for ALTHOUGH-I~s PNOP-2: the (up to this point unexplained) SLIGHT-DECRFASE of NR-UNEMPIK)YED GLOBAL.</Paragraph> </Section> class="xml-element"></Paper>