Dr. Richardson says, "There is no such thing as an absolute threshold because stimulus detection depends on a number of factors beside the physical intensity of a stimulus and the sensory abilities of the observer." Dr. Richardson is most likely an advocate of which theory?

Signal detection theory                        

Explanation:

In psychology, signal detection theory is also referred to as detection theory and it is described as a phenomenon to measure of identifying the capability of a person to differentiate between random patterns and information-bearing patterns that tend to distract from a piece of particular information.

In other words, it is described as a state in which the detection of a specific stimulus depends on the psychological or physical state of the person as well as the intensity of the given stimulus.

In reference to the question, Dr Richardson is most likely an advocate the signal detection theory.