Our senses provide multiple signals that can be used for perception, but the information the signals provide is far from perfect: signals are not always sufficient to determine uniquely their environmental causes and are affected by noise due to transduction and neural processing.
Compliance is the amount of physical deformation of an object for the amount of force applied. Compliance perception (i.e., object softness) is a case of active sensing, because we need to interact with the object in order to collect sensory information.
The perception of 3D shape is obtained through a complex interplay between local analysis and contextual information. For example, when we observe an object we integrate multiple sources of depth information, called cues.
Correct timing (whether it is measuring reaction time, presenting synchronous multisensory stimuli, or providing online feedback) is fundamental in several types of psychophysical research. The connections between the different components of digital computers introduce delays and asynchronies in the stimuli presented and in the recorded response time.
Time is a critical feature of signals arriving from multiple sensory modalities. Simultaneity between multisensory stimuli, for example, can be an indication of which signals originate from a common source, and artificially introduced asynchronies can prevent integration or can dramatically modify perception of the event.