Does Variation in Lexical Sentiment Scores Reflect Emotional Polysemy and Ambivalence?

To measure the emotional meaning of words, numerical sentiment scores are ascribed to them. However, within individual words these scores show variation: within and across annotation surveys, across linguistic contexts, and across semantic neighbors. While such variation could be set aside as undesirable noise, this study examines to what extent variation in lexical sentiment scores is in fact informative of the degree of the emotional ambiguity of words. Four different ways of estimating emotional polysemy and ambivalence are employed to analyze a set of 117 German words. Data from 16 sentiment dictionaries, an additional sentiment survey conducted for this study, automatically annotated contexts drawn from a contemporary German corpus, and pre-trained word embeddings were used for this purpose. These estimates are compared against subjectively rated ambivalence collected through crowdsourcing. It is shown that only variation within and across surveys robustly relates to subjective ambivalence. Context and neighborhood-based estimates, both of which are inherently sensitive to lexical frequency, cannot be shown to be related to ambivalence. This suggests, (i) that variation in lexical sentiment scores across dictionaries and annotators, but not across semantic neighbors and contexts, carries information about emotional meaning, and is hence valuable for cognitive-variationist research, and (ii) that speakers’ retrieval of positive and negative senses of words, in judging the degree of ambivalence, is not strongly affected by frequency, which is fundamental to NLP methods that build on distributional semantics. This implicitly challenges usage-based approaches to semantics that consider frequency as a predominant factor.