Mary Ann Test

The Mary Ann Test is a thought experiment focusing on personal knowledge and consciousness. It poses a scenario where a person, Mary Ann, is a brilliant scientist who knows everything about color vision but has never seen color herself. When she eventually experiences color for the first time, she learns something new—what it is like to perceive color. The test challenges the idea that knowledge is purely factual, suggesting there are qualitative experiences—known as "qualia"—that cannot be explained by information alone. This raises important questions about the nature of consciousness and understanding.