Final answer:
The just-noticeable difference concept defines the minimum detectable difference between two stimuli. A 'single bagger' attitude notes clear, substantial differences, while a 'double bagger' attitude relates to detecting finer, less pronounced changes.
Step-by-step explanation:
The question posed relates to the concept of just-noticeable difference (JND), also known as the difference threshold, which is a term used in psychology to describe the smallest detectable difference between two stimuli that a person can notice a certain proportion of the time. In the context of the provided information, differentiating between a one-pound and two-pound bag of rice represents a substantial difference that would be easily noticed, showing a clear distinction in what we could call a single-bagger attitude which notes prominent differences. However, as the weight of the bags increases, the relative difference becomes smaller, and it becomes much more challenging to perceive a one-pound difference between heavier bags, such as between a 20-pound and a 21-pound bag. This is aligned with a double-bagger attitude, which recognizes the subtlety required when changes are less pronounced.
In the realm of sensory perception, the JND is influenced by a variety of factors, including the initial intensity of the stimulus. The concept is rooted in Weber's Law, which suggests that the JND is a constant proportion of the original stimulus rather than a constant amount. Applied to the rice bags, as the base weight (stimulus intensity) increases, the absolute difference that can be reliably detected also increases.