Investigating Explicitation of Discourse Connectives in Translation using Automatic Annotations (2023)

Abstract: Discourse relations have different patterns of marking across different languages. As a result, discourse connectives are often added, omitted, or rephrased in translation. Prior work has shown a tendency for explicitation of discourse connectives, but such work was conducted using restricted sample sizes due to difficulty of connective identification and alignment. The current study exploits automatic methods to facilitate a large-scale study of connectives in English and German parallel texts. Our results based on over 300 types and 18000 instances of aligned connectives and an empirical approach to compare the cross-lingual specificity gap provide strong evidence of the Explicitation Hypothesis. We conclude that discourse relations are indeed more explicit in translation than texts written originally in the same language. Automatic annotations allow us to carry out translation studies of discourse relations on a large scale. Our methodology using relative entropy to study the specificity of connectives also provides more fine-grained insights into translation patterns.

## introduction discourse connectives such as because and however are considered volatile items in translation: translators often add, rephrase or remove them (e.g. @xcite . prior studies have often focused specifically on whether connectives are added (i.e. the relation sense is explicitated) or removed (i.e. implicitated), and have shown that there is a tendency for explicitation in translation (but this also depends on various other factors, see e.g., @xcite @xcite . the current work focuses on an understudied aspect of connectives in translation, namely when they are underspecified (e.g. connectives like "and" or "but" are compatible with many different types of discourse relations) or highly specific (e.g. the connective "nevertheless" can only mark concessive relations). the question we address is whether we can see a similar pattern of explicitation of connectives in translation for connectives that are already explicit (but possibly unspecific) in the source text. one factor that impedes a comprehensive study of dcs in translation is the (manual) annotation effort that is required for this task. consequently, many studies are restricted to limited samples and a subset of dcs. to facilitate a more comprehensive investigation, we explore an automatic approach to identify and align connectives. specifically, we use language-specific discourse parsers @xcite and a neural word alignment model @xcite to link a large range of connectives and their translations in english and german parallel texts. we test the feasibility of this approach by replicating the well-established explicitation results in our newly created dataset. using an empirical measure of cross-lingual specificity gap, we identify all the cases of (under)specifications instead of a subjectively defined subset. our contributions are: 1) we demonstrate that automatic word alignments and discourse parsers facilitate a comprehensive study of discourse connectives and relations in translation. 2) we show evidence for explicitation in translation, in terms of both insertion and specification of dcs; 3) we compare the cross-lingual specificity of english and german dcs; 4) the automatically aligned and annotated data are publicly available foot_0 . ## results we first look at how connectives are implicitated and explicitated in english and translations, and then we will take a closer look at how the english and german connectives correspond to each other. ## qualitative analysis the qualitative results show that there are more explicitations in translation after counter-balancing implicitation in the other translation direction. now the question is, are these explicitations actually coming from the nature of the translation process, or are they due to the contrast between the two languages or other reasons? we try to gain some insights through a qualitative analysis. we analyze the alignment instances to see if the explicitated translations are obligatory or translation-inherent (see sec. 2.1). this analysis revealed various cases of obligatory explicitation. first, second, for german translation, the translation of but to doch/jedoch differs from the previously discussed obligatory explicitations and might actually be translation-inherent: translators could have translated but to aber, which matches but semantically and also in terms of strength and specificity, instead of specifying the relation with jedoch or doch. to gain further insight into the reason for these explicitations, a trained translator manually analyzed these cases using a "substitution test": we produced an alternative translation using aber, making necessary grammatical changes. if the resulting translation is equally acceptable, then it could be a case of translation-inherent explicitation. we found that in 35% of the but-instances that were translated into doch/jedoch, these more specific could have been chosen because the resulting syntactic or stylistic structure is preferred; that is, they do actually appear to be cases of obligatory explicitation. for example: it is important to have eu and national targets, but it is also important to have a european directive... es ist zwar wichtig, ziele auf eu-und einzelstaatlicher ebene zu setzen, doch ist es ebenso wichtig, eine europäische richtlinie zu schaffen... in this case, having chosen zwar in the previous clause, the translator likely used doch, because they often occur together. but in 65% of the cases, the use of aber is equally acceptable, and thus these cases appear to represent translation-inherent explicitation. for example: its starting point is the european year against racism 1997 but the context has moved on significantly. ausgangspunkt war das europäische jahr gegen rassismus 1997, doch/aber der kontext wurde seither beträchtlich weiterentwickelt. among these acceptable cases, in 38% of the total cases, doch or jedoch sometimes fit better to the formality of a parliament discussion, while but is a lighter dc typical in spoken english, for example: but as has been pointed out, the adoption of a rigorous definition of the precautionary principle is crucial. doch, wie bereits festgestellt wurde, ist dabei die verabschiedung einer strikten definition des vorbeugeprinzips von entscheidender bedeutung. one possible explanation is the domain gap between the source and target texts. the source texts of the europarl corpus are prepared speeches of the parliament, while the target texts are the published translation of these scripts. in other words, the source texts are prepared to be spoken while the target texts are for reading. this could be a reason that the discourse relations in the translated texts of the europarl corpus are more specified than the original texts, corresponding to the situational and translation-task variables as discussed in @xcite . analysis on data from another genre could confirm this domain and genre effect. ## discussion the current study investigated explicitation and implicitation of discourse connectives in english-german parallel texts. to gain a comprehensive insight of the patterns underlying explicitation, we exploited an automatic approach to connective identification and alignment, which allowed us to study a large variety of connectives (173 english and 126 german connective types) and many samples per language (8058 english and 9739 german connectives were identified in our dataset). we evaluated the feasibility of this approach by first studying whether we could replicate the established effect of explicitation in translation between english and german texts. we furthermore extended existing findings by defining explicitation in a more finegrained sense as specification of the relation sense, and investigating whether we can see a similar pattern of explicitation of connectives for those connectives that were already explicit in the source text. our quantitative results provide strong evidence for the explicitation hypothesis: taking into account the counter-balance of implicitation in the opposite translation direction, there is still considerable more explicitation in translation. manual qualitative analysis suggests that a domain effect may have played a role. these findings are in line with already established effects in prior work, and thus support the reliability of the insights that the automatic approach can provide. we also propose a novel method of studying explicitation in translation, namely by considering the relative entropy of corresponding connectives in parallel text. our results showed that the general pattern of explicitation in translation replicates to specification of connectives. furthermore, we found that english connectives are generally less specific than german ones, considering all types of connectives and their translation in our data. the large-scale alignments provide additional insights, such as the fine-grained interaction between relation type and explicitation strategy across different languages. such analyses would not have been possible without taking into account how all types of dcs are translated within the same span of text and a well-defined measure to identify cross-lingual specificity gap. we conclude that discourse relations indeed tend to be explicitated in translation. our proposed automatic approach is feasible for studying translation of connectives in parallel text. we were able to replicate known effects for german-english translations and extend these findings to specification of connectives using relative entropy. the crosslingual analysis in large scale allows us to identify language-specific patterns in discourse production, which is useful for the generation of multi-lingual discourses. future work will focus on applying a similar methodolgy to less studied language pairings to gain further insight into the generalizability of dc translation and production patterns.