Visualising Changes in Semantic Neighbourhoods of E nglish Noun Compounds over Time (2024)

Abstract: This paper provides a framework and tool set for computing and visualising dynamic, time- specific semantic neighbourhoods of English noun-noun compounds and their constituents over time. Our framework not only identifies salient vector-space dimensions and neighbours in notoriously sparse data: we specifically bring together changes in meaning aspects and degrees of (non-)compositionality.

## introduction noun compounds (ncs) such as fairy tale and gold mine represent a type of multiword expressions (mwes) whose meanings are semantically idiosyncratic to some degree, i.e., their meanings are not necessarily fully predictable from the meanings of their parts @xcite @xcite . while the restricted compositionality of ncs has been explored extensively and across research disciplines from synchronic perspectives @xcite @xcite @xcite @xcite , the field is still lacking an adequate amount of empirical large-scale approaches towards diachronic models, in order to explore the emergence and changes of compound meanings over time. up to date, @xcite and @xcite exploited the google n-gram corpus and information-theoretic as well as cosine distance measures to predict the compositionality of the compounds in @xcite , and to detect novel compounds, respectively. maurer et al. (2023) the current study contributes to the so far limited computational models and insights on the diachronic development of nc compositionality. we provide a framework and a tool set for computing and visualising semantic neighbourhoods of english ncs over time. by focusing on semantic neighbours we explicitly target changes in the salient meaning aspects of ncs; more specifically, we bring together semantic neighbourhoods of ncs and their constituents, thus aligning changes in meaning aspects and degrees of compoundconstituent (non-)compositionality. a major sidechallenge is concerned with identifying an appropriate set of vector-space dimensions, both regarding the semantic interpretations of the dimensions and regarding the notorious sparse-data problem in historical corpus data that strongly affects compound representations. the contributions of this paper are the following. the semantic spaces and neighbours of our english compounds and constituents, as well as the visualisation tool which is applicable to also further compound and constituent targets in english and additional languages, are publicly available from https://www.ims.uni-stuttgart. de/data/dia-neighbour-nn . a full list of the mapping of the pos tags can be found in appendix a. to analyse changes over time, the data was segmented into specific timeslices. the selected timeslices are: 1810-1829, @xcite , with each range being inclusive. ## temporal compound visualisation we implemented two methods to visualise timespecific compounds in semantic space. ## conclusion this study used a corpus-based computational approach to examine the semantic evolution of noun compounds in historical american english, thus contributing to the field of diachronic computational linguistics by providing a methodologically robust tool set for analyzing temporal changes in compound semantics. future research could expand upon this foundation by exploring other types of multiword expressions.