text: The model has been extended to both 2D and 3D with more complex means of defining the accuracy component of the movement (Bootsma et al., 1994; I. S. MacKenzie & Buxton, 1992; Zaal & Bootsma, 1993). The block size manipulation in the current experiment is consistent with one of the dimensions manipulated by Salln√§s and Zhai (2003). However, they utilized different cube sizes to manipulate ID, which effectively changes target sizes in three different dimensions concurrently.