Comparing the Threshold and Prototype Model for Gradable Adjectives

In logical theories of meaning, threshold and prototype models are two distinctive formal approaches. In cognitive science literature, however, where the two models are operationalized, there is support for the use of a threshold model in categorization (Schmidt, Goodman, Barner, & Tenenbaum, 2009; Ramotowska, Haaf, Van Maanen, & Szymanik, 2022) as well as support for the prototype model (Douven, 2016; Douven, Wenmackers, Jraissati, & Decock, 2017), and in many cases the two models are used interchangeably (Kruschke, 2008). We test for the case of relative gradable adjectives whether a) there is a difference between predicted degrees of membership from the two models when relying on explicit reports of threshold and prototype values, and b) which of the models better predicts behavioral data from categorization tasks. Results suggest that prototype and threshold models are highly predictive of behaviour in a categorization task and that the two models yield similar results with a slight advantage of the threshold model.