Measuring Semantic Content To Assess Asymmetry in Derivation

Motivation and theoretical perspective. Morphological derivation is the process of forming new words (derived terms) from existing ones (base terms) such as nominalization. E.g., the English noun dancer is derived from the verb dance by applying the agentive suffix -er. In contrast to inflection, which changes the grammatical properties of the base term, derivation arguably creates a new lexical item. Derivation combines (typically regular) surface changes (add -er) with semi-regular semantic shifts (-er can refer to, among others, agents and instruments of the respective verbs), and has received interest in theoretical linguistics (Plank, 1981) and recently in computational linguistics (Lazaridou et al., 2013). In this study, our goal is to investigate a theoretical claim about derivation with CL methods. The claim is that derivation is an inherently directional process with respect to meaning. Laca (2001) claims that “a derived lexeme presupposes the lexeme it is derived from,” suggesting that the meanings of derived terms involve additional meaning components. Being a dancer presupposes a dancing event, as well as additional, more specific information about the relation to the event. This forms our hypothesis: