shared task on automatic identification of verbal MWEs - edition 1.1 (2018)
Verbal multiword expressions versus metaphor
Another phenomenon closely related to VMWEs is metaphor. According to (Shutova 2010), "a metaphor occurs when one concept is viewed in terms of the properties of the other. In other words it is based on similarity (presence of common characteristics) between two concepts".
Many VMWEs, especially idioms, are based on metaphors. For instance, to take the bull by the horns means to address a problem (the bull) starting with its most challenging aspect (the horns). To set the world on fire is to do something extraordinary and get the admiration (set on fire) of other people (the world), to put all one's eggs in one basket means to rely on one particular course of action (a basket) for success rather than giving oneself several possibilities.
However, verbal metaphors are not always VMWEs. Consider the newspaper title "simple steps to lift your dark cloud of stress", and the extract of a poem by Wordsworth, cited by Shutova: "and then my heart with pleasure fills, and dances with the daffodils". The metaphorical expressions to lift dark cloud of stress to relax and my heart ... dances with the daffodils I am happy are not semantically compositional. These expressions, however, were probably constructed for the needs of one article/poem only and are not sufficiently established in the common vocabulary to be considered VMWEs.
The distinction between MWEs and metaphors is a relatively unstudied and open question. There are few precise tests, other than statistical, which would allow human annotators to resolve it reliably. Gross (1982) gives some clues on the reproducibility and predictability of metaphors. It remains to be seen how heavily this problem will impact the annotation of texts selected for our shared task. We suggest that the annotators take notes of such cases and discuss them within their communities, both local and international.