What is the difference between an absolute threshold and a decision threshold?

Answer 1

An absolute threshold was seen as a hypothetical barrier that incoming stimuli must overcome before they can be perceived, it was based on the ability to pass through the threshold based on absolute judgements about a single stimulus. In the case where a person were to, for example- detect a light, the strength of said light would have to be strong enough to pass the threshold for an observer to perceive it, it was generally based on the observer's ability to detect a signal.

In reality however, there is no such threshold that splits the stimulus dimension into detectable and undetectable components. Rather, a stimulus must yield a sensation that exceeds the decision criterion (beta) for even the weakest signal to be perceived, so a decision threshold is the stimulus that elicits the response or perception. The detectability and reporting of the presence of a signal- or the light- are both factors because the decision threshold must be passed and the results from the strength of the stimulus, for example the light- as well the evidence of yielding such strength, must be plausible. Only in this case, do we have correct detection of a signal.

Answer 2

The absolute threshold refers to the minimum level of stimulation needed for a sensory system to detect a stimulus. The decision threshold is the point at which a person decides whether a stimulus is present or absent based on the strength of the stimulus compared to a set criterion.