Institute for Mathematical Behavioral Sciences

The Ratcliff diffusion model for simple two—choice decisions (e.g., Ratcliff, 1978; Ratcliff & Smith, 2004) has two outstanding advantages. First, the model generally provides an excellent fit to the observed data (i.e., response accuracy and the shape of RT distributions, both for correct and error responses). Second, the parameters of the model can be mapped to latent psychological processes such as the quality of information processing, cautiousness, and response bias. In recent years, these advantages of the Ratcliff diffusion model have become increasingly clear. Current advances in methodology allow all researchers to easily fit the diffusion model to data; new theoretical developments shed light on the optimality and possible neural underpinnings of the model; and recent applications to aging, IQ, and lexical decision highlight the added value of a diffusion model perspective on simple decision making.