Reflection in artificial intelligence, notably used in large language models, specifically in Reasoning Language Models (RLMs), is the ability for an artificial neural network to provide top-down feedback to its input or previous layers, based on their outputs or subsequent layers. This process involves self-assessment and internal deliberation, aiming to enhance reasoning accuracy, minimize errors (like hallucinations), and increase interpretability. Reflection is a form of "test-time compute," where additional computational resources are used during inference.