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<?xml version="1.0" standalone="yes"?> <Paper uid="C96-1050"> <Title>Mithras Annexe</Title> <Section position="5" start_page="0" end_page="0" type="metho"> <SectionTitle> ATION and ENABLEMENT (Goldman, 1970) re- </SectionTitle> <Paragraph position="0"> lations which have the advantage of being tbrmally specified (see e.g.(Pollack, 1986; Balkanski, 1993)), and need to be expressed regularly within instructional texts. In section 2, we give a brief definition of generation and enablement, before going on in section 3 to describe how the two relations are realised in the corpus of Portuguese, English, and French instructions.</Paragraph> </Section> <Section position="6" start_page="0" end_page="292" type="metho"> <SectionTitle> 2 The Semantic Relations </SectionTitle> <Paragraph position="0"> Generation and enablement are relations that can hold between pairs of states, events, processes, or actions. A simple test of generation holding between action pairs is whether it can be said that by performing one of the actions (a) under appropriate conditions, the other (/9) will automaticMly occur (Pollack, 1986). If so, it can be said that c, generates/). The two actions must be performed, or perceived to be performed, by the same human agent, and the two actions must be asymmetric (i.e. if a generates fl, then fl cannot generate a).</Paragraph> <Paragraph position="1"> Simple examples of generation are ~ follows: 3 (1) Heat gently to soften the coating.</Paragraph> <Paragraph position="2"> (2) Dial the numbers of the Mercury authorisa null tion code by pressing the appropriate numbers on the keypad.</Paragraph> <Paragraph position="3"> In example 1, the action of heating gently ha~s the effect of softening the coating. In example 2, advantages of this approach over the inherent limitations of a translation-based approach to producing pressing the correct keypad numbers has the automarie effect of dialing the numbers of the Mercury authorisation code. In each case, by performing the C/t action (or set of actions), the user has automatically performed the fl action. Note that the two actions can bc presented in either order: generatiNG first, or generatED first.</Paragraph> <Paragraph position="4"> q'he term cnablemeut is commonly used to refer to the procedural relation between preconditions and actions. It obtains between two actions where the execution of the first brings about a set of conditions that are necessary, but not necessarily suJJicienl for the subsequent performance of the second (Pollack, 1986). This is different from the generation ('rose, since enablement requires the further intervention of an agent - and it need not be the same agent - to bring about the fl eventuality. null (3) (?lose cover and test a.s recornmended in 'Operation' section.</Paragraph> <Paragraph position="5"> (4) l)br prolonged viewing, ttle slide may be pushed downwards and then backwards until it locks under the ledges at each end of the slot.</Paragraph> <Paragraph position="6"> Example 3, taken from the instructions for a household smoke alarm, shows the enabliNG action appearil, g tirst: closing the cover enables testing to take place, but does not automatically result in a test. Example 4, front the instructions for a home photographic slide viewer, presents the enablED action ~ prolonged viewing - first, and describes to tile user what must be done to facilitate it.</Paragraph> <Paragraph position="7"> These two relations have been formalised by Pollack (1986) and Balkanski (1993) for the purposes of plan recognition, and can be represented in a plan formalism that is a simple extension of STRll)S-styled operators developed by Fikes (1971) and expanded in the NOAII system (Sacerdoti, 1977). \[Iere, we summarise the two relations in the form of the following planning statements: ,, (~ generates fl iff c~ is the body of a plan e whose goal is ft.</Paragraph> <Paragraph position="8"> ,, oe enables fl if ce is a precondition of a plan e and/3 is the goal of plan e, or iffl is the body of e and t~ is a preconditkm of/3.</Paragraph> <Paragraph position="9"> In order to generate instructions clearly, it must be obvious which, if either of the two relations is intended at any given point: eonflmion of one with the other will lead to inadequte, incomplete, or even dangerous execution of the t~k described.</Paragraph> </Section> <Section position="7" start_page="292" end_page="296" type="metho"> <SectionTitle> 3 From Semantics to Syntax </SectionTitle> <Paragraph position="0"> Ilow, then, are generation and enablement realised in the three languages of study? In what follows, we look at the syntactic resources that are used in each language to convey the two parts of the two relations, and look at tile constraints on tile ordering of tile two parts; then, at what discourse markers play a role in further ensuring the clarity of the relation intended, and finally show how different rhetorical interpretations result from these choices. Together, these factors explain a significant amount of the cross-linguistic wtriation that occurs within the instructions sublanguage, in what follows, however, it is not our intention to suggest an ordering tbr the set of de~ cisions that need to be made for generation: so far, our research suggests a complex interaction of factors is involved in choice of expression, and tim ther research is required to establish their relative priorities in the decision-making process.</Paragraph> <Paragraph position="1"> Our corpora for the study consisted of 65 exampies of generation, and 65 examples of enablement for each of the three languages of study. 4</Paragraph> <Section position="1" start_page="292" end_page="295" type="sub_section"> <SectionTitle> 3.1 Syntacti(. Resources </SectionTitle> <Paragraph position="0"> The distribution of expressions among the two components tED and ING) of the generation relation for Portuguese is shown in figure 1 '~.</Paragraph> <Paragraph position="2"> p,.<v,~ / ~1 degl 21 31 '21 '~/~.4 Subjunctive/ 4 I i I 5 I degl o \[ o/a.8 Nominal 1 4 5 0 0 0 3 8 K k_4\[_ '51 ~ (~ )\] :.~ Figure l: Expressions of(~eneral, ion: Portuguese Three strong patterns emerge in the data. First, two syntactic forms, infinitives and imperatives, dominate; together they account for over 80% of the action expressions in tile data set. Second, tile overlap in expressions between ED and ING elements is relatively small; it is confined to only two of the five types of expressions: infinitives and passives. Finally, these data suggest that the order of occurrence of the ED and ING components in a sentence does not interact with decisions of choice of expression: in general, once a syntactic form is made available lbr expressing El) or ING components, it can be used irrespective of the order of occurrence of that component in the sentence.</Paragraph> <Paragraph position="3"> French (see figure 2) shows a strong preference for the use of the two forms of imperative (imperative- simple and imperative-infinitive), the infinitive anti tile gerundive. Overall, however, there is a more even spread between choices than 4 In order to satisfy ourselves that the linguistic ex-amples in the corpus were indeed representative realisations of the two semantic relations described, we also perfornmd an experiment requiring naive informa.ts to identify linguistic cxamples as cases of one or other relation. There was a high degree of agreement (m what constituted all example of each.</Paragraph> <Paragraph position="4"> ~This includes only those syntactic categories for which we found more titan one example in the d~tta set; for this reason the percentages do not total to 100.</Paragraph> <Paragraph position="5"> French, unlike Portuguese and English, has two forms of imperative. One is identical in form to the infinitive of the verb and is usually associated with a generic addressee: a 'public' form of address. The imperative-simple, on the other hand, is identical in form to the second-person plural 6 indicative of the verb and its use is associated with identifiable addressees. The fact that this form accounts for 40% of imperatives in the corpus may be seen as evidence for the increasingly user-oriented style of instructions for household appliances.</Paragraph> <Paragraph position="6"> Unlike in Portuguese, ordering does play a role in French. Both imperative-infinitive and imperative simple expressing generatED occur first, while a gerundive expressing generatiNG occurs second.</Paragraph> <Paragraph position="7"> In addition, Portuguese showed a strong differentiation between ED-specific and ING-specific forms, and therefore little overlap, but in French, overlap is much greater: only one form, the gerundive, is constrained to one part of the semantic relation (generatiNG).</Paragraph> <Paragraph position="8"> English appears the most permissive in terms of both overlap between ED and ING-bearing expressions, and lack of influence of ordering - a combination of the characteristics of the other two languages. While there is a strong preference for infinitive and imperative forms, the influence of the part of the semantic relation only extends, as in French, to a single form: the appearance of the infinitive as an expression of generatED rather than generatiNG. The influence of ordering appears to be at the level of weak preferences, in line with Portuguese, rather than the stronger role seen in French generation. The distribution of expressions in English generation is shown in figure 3.</Paragraph> <Paragraph position="9"> 1 Ge.0r~G~.eratING \[lst\[2naITotal t 1st 2ha I Tota~ 1 1251 7 I 32\] 0 O 0124.4 I \[ 8J 1 I 9 I 10 29 I 39 136.71 I 41 3\] 7 I 1 0 11 6.11 i11 l I 2 I .3 20 23\]19.0 I i 81 4 I 12 I 3 o I 3111.5 I Portuguese uses a very small subset of of the available syntactic resources of the language to express enablement: only infinitives, imperatives (together, over 85% of the data set) and nominals 6We ignore here the singular, familiar imperative.</Paragraph> <Paragraph position="10"> express enablement 7. While there was no ordering preference in Portuguese generation, there is an ordering constraint on enablement: imperatives expressing ED do not appear first. The distribution of syntactic forms (figure 4) shows that, while there is a high degree of overlap in terms of expression of 1NG or ED, a system of preferences operates: the infinitive is three times as likely to be used for the ED than ING component, while the imperative is twice as likely to be used for ING French has a relatively broad range of expressions available for enablement (see figure 5)-much wider than Portuguese. As was the case for generation, French enablement shows a strong ordering preference: when an imperative is used as enablED, it must be placed second (if expressing generatED, it must be placed first). The gerundive is strongly marked for generation, and in the rare cases it is used in enablement is restricted to a single semantic role: expressing enabliNG, rather than enablED-the only French expression so restricted. Euablement is most regularly expressed by the imperative-infinitive.</Paragraph> <Paragraph position="11"> In English (figure 6), although the imperative is the most popular expression of enablement, (over 60% of tokens), when it expresses the enablED part of the relation, it must appear second: to place it first would be misleading, as it would imply that this action should be performed first.</Paragraph> <Paragraph position="12"> There is also a constraint arising from the part of the semantic relation being expressed: infinitives do not express the enabliNG action. Infinitives are only capable of conveying a goal, and the en- null The relationship with actual temporal ordering of events plays no role in determining ordering in the case of avant de and apr~s followed by an infinitive: the two possible orderings are eqnally likely. In the case of avast and apr& followed by a nominal, there is a strong preference for placing the prepositional phrase containing the nominal first. Clearly, this yields an iconic ordering in the cause of apt& and a non-iconic ordering in the case of avant.</Paragraph> <Paragraph position="13"> Apr~s ddpoussidrage, appliquerdeux couches de peinture vinylique.</Paragraph> <Paragraph position="14"> After dusting, apply two coats of vinyl paint.</Paragraph> <Paragraph position="15"> (6) Avant l'emploi, faites tremper le boyau dans de l'eau ti6de.</Paragraph> <Paragraph position="16"> Before use, soak the tube in warm water.</Paragraph> <Paragraph position="17"> As in Portuguese, though, both rhetorical relations are clearly marked, and there is a similar, Mthough less marked, tendency to view the semantic content of the enablement relation as being one of temporal sequence.</Paragraph> <Paragraph position="18"> English h~s the greatest tolerance of mmmrked discourse relations among the languages studied: only 37 of the 130 clauses examined appeared with a marker of any kind. The majority of markers were instances of by appearing with a nominalisation to convey the generatiNG part of the relation, showing a preference for communicating this semantic content in terms of the rhetorical relation of MF, ANS in English 9 18 of these 19 instances of by appeared when the generatED element was presented first: by is used to signal the MEANS relation when conflmion might otherwise result from a user attempting to perform the generated action, 9As stated at the outset, however, we cannot yet state the ordering of the relevant semantic, syntactic, and rhetoricM decisions.</Paragraph> <Paragraph position="19"> presented first, rather than the generating action.</Paragraph> <Paragraph position="21"> The markers simply and just appear only with generatiNG imperatives. For appears only with NP, and marks only generatED elements. So that, which appears rarely, marks only generatE1) elcments. The less common and, if and when couhl appear with either ING or 1'3).</Paragraph> <Paragraph position="22"> Even though English does not mark the two parts of the generation relation explicitly by means of discourse markers, the combination of ordering, syntax, and rhetorical relation results in all but one c~e in an unambiguous interpretation.</Paragraph> <Paragraph position="23"> PUIU'OSF,, is the only relation that is expressible in both ED-first and ING-first order: in fact, it is only infinitives and for with a nominal that can appear either before or after their main chmse.tdeg The range of rhetorical relations available for the expression of generation is, however, the greatest of the three languages, consisting of a superset of the relations adopted in French and Portuguese.</Paragraph> <Paragraph position="24"> Enablement in English is expressed most fl'equently by SEQUENCI.;, which, with appropriate temporal markers, can appear in both iconic and non-iconic order: the few non-iconic cases (5) are n,arked with before, follow ling\] by \[ed\], and followed by. PURPOSE is also a frequent interpretation. For enablement, some discourse markers are exclusive, and some ambiguous. If appears exclusively with the E1)-first presentation, and and, then, followed by, follow X by, and now only ap-pear with the ING-first ordering, ~ do commas.</Paragraph> <Paragraph position="25"> 7'0, for and before are ambiguous. Finally, just and simply are markers that only appear with the ING clement, but there is always another marker that appears in the ED element in conjunction with them.</Paragraph> <Paragraph position="26"> ldeg'l'hese alternations in ordering are discussed in (Vander l,inden, 1.993) in terms of the intention t.o convey optionality or oblig~ttoriness of tile action in t|te matrix clause.</Paragraph> <Paragraph position="27"> As was the case with generation in English, there is a high degree of overlap between all other expressions of the two parts of the relation.</Paragraph> </Section> <Section position="2" start_page="295" end_page="296" type="sub_section"> <SectionTitle> 3.2 Discourse Markers and Rhetorical Relations </SectionTitle> <Paragraph position="0"> Very strong correlations appear between particular choices of semantic relation and syntactic form on the one hand, and the appearance of discourse markers and/or a strong bias towards a particular rhetorical interpretation on the other. Our analysis shows that selection of syntactic expression and local discourse relation strongly interact, and provides a rather clearer picture of the influences that bear on the mapping front semantics to syntax. null A particularly important element to emerge is the language-specific nature of the choice of rhetorical relation, a notion which we express for the moment in terms of l~ST-style rhetorical relations, of. (Mann and Thompson, 1988). The analysis represents a careful but intuitive interpretation of what rhetorical relation would be retrieved, by a native speaker of the language, front the particular combination of syntax, discourse marker, and content. What triggers these interpretations is constrained both by semantic content and by the conventions and syntactic resources available within the languages of study.</Paragraph> <Paragraph position="1"> Portuguese appears to have obligatory signalling of discourse relation by a discourse marker, or at the very least by punctuation s . Three discourse relations are available for generation (PUR-POSE, CONDITION, RESULT) and two for enablement (PURPOSE, SEQUENCE). For generation, the dominant relation is PURPOSE (80%); for enablement it is SEQUENCE (72%). The overlap in the syntax of generation vs enablement sentences is confined to expressions of PURPOSE. Figures 7 and 8 show the relationships between semantic relation and syntax with an overlay of discourse: rhetorical relations and discourse markers.</Paragraph> <Paragraph position="2"> The figures show a strong and unambiguous re-SThis can be compared with the finding presented by (Moser and Moore, 1995) in their ACL-95 presen-. tation, that discourse cues are significantly more likely to occur when the 'contributor' component of the relation PRECEDES the 'core' in English dialogues.</Paragraph> <Paragraph position="3"> lationship between rhetorical relation, discourse marker, and syntax. There is a strong tendency to present generation in terms of the rhetorical relation of I'URPOSE, which is marked almost invariably by para or para que (so that), both of which can only take a nominal or infinitival expression. SEQUENCE, on the other hand, is signalled by temporal connectives such as antes de (before), depois de (after) or apes (afte,9, by the connective e (and) or implicitly by the use of a comma between the elements of a string of imperatives. For Portuguese enablement, two relations are preferred: PURPOSE and SEQUENCE, with a strong preference for the latter. Again, the markers of each rhetorical relation are distinct.</Paragraph> <Paragraph position="4"> imperative I infinitive imperative I ! ....... inal, infinitive} imperative I !mperative imperative \[imperative Portuguese: Enablement 3.2.2 h.encl~ig.re s: In French, discourse markers do not accompany all expressions of generation. However, where they do occur, the markers unambiguously assign the expressions to one or other of the plan elements: body (si, en and par) or goal (pour, afin de, and de fafon it). While Portuguese generation is overwhelmingly expressed through the rhetorical relation of PURPOSE, in French it is more evenly distributed between PURPOSE and MEANS, with a small showing for CONDITmN. Although not shown in the figure, there is only one case in French generation where the choice of ordering of the elements and the choice of marker-plus-expression are not mutually constraining: this is when the preposition pour is followed by an infinitive. In this case, the two orderings of the relation The expression of enablement in French instructions (figure 10) is limited to two rhetorical relations: SEQUENCE and PURPOSE. Situations where the choice of ordering of the elements and the choice of marker-plus-expression are not mutually constraining are limited to the PURPOSE discourse relation marked by pour and the SEQUENCE discourse relation marked otherwise than by hy-</Paragraph> </Section> </Section> class="xml-element"></Paper>