Final answer:
The most common mistake made when observing around the corner is due to inattentional blindness, where an individual fails to see an unexpected stimulus because their attention is focused on another task. This phenomenon exemplified by missing a person in a gorilla suit in a famous study by Simons and Chabris, has implications for various practical scenarios, including lighting design.
Step-by-step explanation:
When considering the most common mistake made when observing around the corner, we refer to the concept of inattentional blindness, which is a psychological phenomenon where an individual fails to perceive an unexpected stimulus in plain sight. This occurs when the attention is dedicated to another detail or task, and thus the unexpected object or event is not registered by the observer. One of the landmark studies demonstrating this principle was conducted by Daniel Simons and Christopher Chabris, where participants were asked to count basketball passes and missed seeing a person in a gorilla suit walking among the players.
Inattentional blindness is not only fascinating but also has practical implications, particularly in areas such as driving safety and security monitoring, where overlooking an unexpected object can have serious consequences. In terms of lighting design mentioned in the initial query, a similar principle applies: novice designers might focus so much on some elements of the design that they overlook others, leading to a less effective or safe lighting environment.
This relates to another psychological effect of how observers interact with light. The Misconception Alert highlights that observers often do not realize that light rays come from all parts of an object, pass through every part of the lens, and contribute to forming the final image, which could be an error by those new to lighting design or visual observation tasks.