Rank-1 accuracy

Rank-1 accuracy measures how often a system correctly identifies an item on its first guess. For example, in facial recognition, it checks how often the system's top prediction matches the actual person. If out of 100 images, the system correctly identifies 80 on its first attempt, the Rank-1 accuracy is 80%. It is a straightforward way to evaluate the system’s immediate correctness, reflecting how often it gets the best guess right without considering other potential options.