The model identifies a spatial coordinate frame within which the sensorimotor apparatus produces movement. Its spatial nature simplifies its coupling with spatial reference frames used concurrently by vision and proprioception. While the positional reference frame addresses the performance of spatial tasks, it seems to have little to say about movements involving energy expenditure as the principle component of the task.

Perception of (and during) events is a necessary feature of any perceptual theory. Norman's dual-process approach cannot account for the perception of events without substantial interactions between the dorsal and ventral systems. These interactions, as outlined by Norman, are highly problematical. The necessity for interactions between the two systems makes the distinction useless.

Roger Shepard's description of an abstract representational space defined by landmark objects and kinematic transformations between them fails to successfully capture the essence of the perceptual tasks he expects of it, such as object recognition. Ultimately, objects are recognized in the context of events. The dynamic nature of events is what determines the perceived kinematic behavior, and it is at the level of dynamics that events can be classified as types. [Shepard].