A Sentiment-annotated Dataset of E nglish Causal Connectives (2020)

Abstract: This paper investigates the semantic prosody of three causal connectives: due to, owing to and because of in seven varieties of the English language. While research in the domain of English causality exists, we are not aware of studies that would cover the domain of causal connectives in English. Our claim is that connectives such as because of link two arguments, (at least) one of which will include a phrase that contributes to the interpretation of the relation as positive or negative, and hence define the prosody of the connective used. As our results demonstrate, the majority of the prosodies identified are negative for all three connectives; the proportions are stable across the varieties of English studied, and contrary to our expectations, we find no significant differences between the functions of the connectives and discourse preferences. Further, we investigate whether automatizing the sentiment annotation procedure via a simple language-model based classifier is possible. The initial results highlights the complexity of the task and the need for complicated systems, probably aided with other related datasets to achieve reasonable performance.

## introduction and background examination and extraction of sentiment (sentiment analysis, sa) from text traditionally rely on the coarse distinction between positive and negative polarity. the mainstay of the current methodologies is the idea that a text contains a single sentiment about one single topic, as in (1) below @xcite . however, it is now generally acknowledged that sentiment within one topic should be considered at several levels of granularity, as in (2): one domain that is both challenging and useful for sentiment detection is causality -notoriously difficult to analyze (in spite of being regarded as one of so-called "semantic primitives" @xcite ), as it operates both at the level of factual events in the real world, and at the level of "metacausality" -i.e. the speaker's reasoning and exchange between interlocutors (e.g. conclusions and speech acts; see @xcite and the literature on computational methods to detect causality, e.g. @xcite ). one example of a relation that conveys causality at the level of the speaker's reasoning is (3) below: both the causal argument (2nd clause) and the result argument (1st clause) convey the speaker's opinion, i.e. not a result based on a cause in the physical world. while such relations are very common in discourse, producing this type of deep causal explanation is beyond the capability of the existing systems @xcite . attempts have been made in the field to capture causal explanations as, first of all, temporal sentiment analysis to predict causal relations @xcite , and sentiment analysis and causal rule detection @xcite . some studies also utilize discourse connectives as predictors of discourse relation types, for instance, @xcite and @xcite , and indicate that discourse particles such as but, since, or although can be used to improve sentiment classification accuracy. importantly, several linguistic studies have proved that discourse connectives prime or at least support the intended discourse interpretations as real-world consequences or meta-linguistic effects such as conclusions, opinions or speech acts @xcite @xcite . since causality is basic to both human cognition and discourse coherence, our paper intends to further explore the nature of causal explanations and the role of discourse connectives in relation disambiguation by focusing on three causal connectives in english -due to, because of and owing to -from the point of view of their semantic prosodies. semantic prosody has been described at several levels of abstraction (e.g., affective meanings of a given node with its typical collocates) @xcite , the discussion of which would be beyond the scope of this paper. the view adopted in the following is that semantic prosody is a feature of the node word that dictates the general environment which constrains the preferential choices of this word. as a result, it can affect wider stretches of text and so the words often tend to co-occur with either 'negative' ('bad', 'unpleasant') or 'positive' ('good', 'pleasant') collocates @xcite , see also @xcite ). a related idea is colligation, i.e. the relationship between a node and grammatical categories. this feature is, however, excluded from our analysis based on the observation that all the investigated connectives follow the standard syntactic pattern: connective + np in their target senses @xcite , for instance: in order to detect the sentiment of the analyzed connectives, our first step was to investigate their general collocational behavior. to this end, we started our study by consulting the oxford english dictionary (oed). 1 while the connectives all have synonymous surface senses, their meanings and functions in natural discourse can be perceived as either negative, positive or neutral. according to the oed, the etymologies of the expressions that the connectives stem from can be assessed as quite negative for both due to and owing to (i.e. "indebted or beholden" for owe and "debt or obligation" for due), and neutral for because ("for the reason that"). however, the target senses we are interested in (i.e. the connective as a compound preposition followed by an np), are all described as relatively neutral: while because of means "by reason of; on account of"; due to is defined as: "as a result of, on account of, because of"; and the target meaning of the connective owing to has been described as: "in consequence of, on account of, because of". we can therefore assume that our connectives are intrinsically neutral. this assumption is important in a study of semantic prosody, since words that have clear negative or semantic prosodies are hard to investigate given their context-neutralizing function (e.g. the verb alleviate remains positive even if accompanied by a clearly negative phrase, such as suffering @xcite ). the conclusion to draw from this part of the investigation is twofold -while the analyzed connectives indeed seem to have quite neutral senses, given their complex etymologies and quite specific semantics (as opposed to that of multi-functional connectives such as so), it can be assumed that they will show tendencies to occur with either favorable or unfavorable events. based on the previous studies within the domain of causality that have indicated that the verb cause has a negative semantic prosody (e.g. @xcite ), which has been demonstrated to prime experimental subjects to think about the same event as negative if preceded by this verb @xcite , it can be assumed that at least some of the connectives in question will exhibit negative collocational behaviour. needless to say, language users may quite flexibly establish the linguistic environment of any phrase (connectives included), based on their communicative and rhetorical purposes (cf. @xcite , on the prosody of the word challenge). in order to establish the type of semantic prosody related to the analyzed connectives, we investigated their immediate linguistic environments and assessed whether the node item occurs with favourable or unfavourable meanings. while the underlying idea was that a specific word/phrase would be found in the context as governing the positive or negative flavour of the sentence, we analyzed at least a whole clause preceding and following the connective. apart from the practical use of our computational method for automatic annotation of the sentiment of discourse connective arguments, our investigation gives us a more detailed understanding of the differences between these near-synonymous connectives in english. our aim has also been to use such differences as a proxy to investigate pragmatics-level language change, by making quantitative comparisons between different english varieties. the same methods could be applied to diachronic studies, given a corpus with sufficiently comparative text over a suitable time span. this goes beyond the scope of the current project. ## research questions while our main contribution in this paper is the annotated resource as such, the original motivation for performing the annotation work is to answer a number of questions on semantic prosody of causal connectives. ## conclusion the main finding of our study is that the three causal connectives analyzed, due to, because of and owing to, are all associated with predominantly negative semantic prosodies. other than this general trend, the distributions of usages do not significantly differ between the connectives, between the analyzed regional varieties of english, or between the arguments (cause and effect). we investigated the possibility of automating sentiment annotations for this project in section 4.4 and our results indicate that the computational model achieves moderate agreement with the annotators despite the limited training data, suggesting that the procedure can benefit more annotations and have potential to be automatized to a good extent after a certain amount of manual annotation. the topics for future work are to involve more human annotators and develop more precise guidelines based on their observations and, also, investigate whether other, larger, sentiment-related resources can be exploited for this task.