Types of metaphors and their structure: An annotation project.

Metaphors are not all equal. Besides identifying metaphors in texts, metaphor annotation should therefore also aim to make explicit the distinction between different types of metaphor. The annotation guidelines presented in this paper have been conceived precisely with this objective in mind, and consist of a set of steps aimed at identifying different types of metaphors (i.e., conflictual and consistent, creative and non-creative ones) and highlighting their internal structure (by marking focus, frame, and covert concepts that may result from their interaction). Annotating the structure of metaphors also makes it possible to mark connections between metaphors occurring within a given text, such connections being defined by the presence of a shared frame and a consistent relation between the foci of the metaphors. The presentation of the annotation guidelines is followed by a discussion of their strengths, which are primarily theoretical, and of their limitations, which are primarily practical. The specific challenges that different types of metaphors pose to annotation are also examined and illustrated through examples from different text genres.